Surgical stapling instruments including a cartridge having multiple staple sizes

ABSTRACT

A surgical stapling apparatus includes a staple cartridge and an anvil member. The staple cartridge includes a plurality of surgical fasteners disposed in rows of retention slots. The staple cartridge may have an annular or linear configuration of retention slots. The tissue contacting surface of the staple cartridge may be tapered or stepped. The anvil member has a tissue contacting surface that includes a number of pockets arranged for substantially aligning with the retention slots. In addition, the tissue contacting surface of the anvil member may complement the tissue contacting surface of the staple cartridge.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/716,523, filed Dec. 17, 2012, now U.S. Pat. No. 8,608,047, which is acontinuation of U.S. patent application Ser. No. 13/419,586, filed Mar.14, 2012, now U.S. Pat. No. 8,579,178, which is a continuation of U.S.patent application Ser. No. 13/286,544, filed Nov. 1, 2011, now U.S.Pat. No. 8,157,152, which is a continuation of U.S. patent applicationSer. No. 12/916,926, filed Nov. 1, 2010, now U.S. Pat. No. 8,070,035,which is a continuation of U.S. patent application Ser. No. 12/556,760,filed Sep. 10, 2009, now U.S. Pat. No. 7,837,081, which is a divisionalof U.S. patent application Ser. No. 12/178,739, filed Jul. 24, 2008, nowU.S. Pat. No. 7,588,174, which is a divisional of U.S. patentapplication Ser. No. 11/974,637, filed Oct. 15, 2007, now U.S. Pat. No.7,455,676, which is a continuation of U.S. patent application Ser. No.11/592,566, filed on Nov. 3, 2006, now U.S. Pat. No. 7,398,908, which isa continuation-in-part of U.S. patent application Ser. No. 11/436,222,filed on May 18, 2006, now U.S. Pat. No. 7,401,721, which is acontinuation-in-part of U.S. patent application Ser. No. 11/204,060,filed on Aug. 15, 2005, now U.S. Pat. No. 7,407,075, the entire contentsof each of which are hereby incorporated by reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates to surgical stapling instruments and,more particularly, to surgical stapling instruments including acartridge having multiple staple sizes.

2. Background of Related Art

There are several known types of surgical stapling instrumentsspecifically adapted for use in various procedures such as end-to-endanastomosis, gastrointestinal anastomosis, endoscopic gastrointestinalanastomosis, and transverse anastomosis. Examples of staplinginstruments for these various procedures can be found in U.S. Pat. Nos.5,915,616; 6,202,914; 5,865,361; and 5,964,394.

Each surgical stapling instrument includes an anvil which isapproximated relative to a staple cartridge. The staple cartridgetypically has one or more laterally spaced rows of staples which,depending on the particular stapling instrument, may be arranged in alinear or non-linear configuration. The anvil includes staple formingdepressions which are aligned with and/or in registration with thestaple slots of the staples in the cartridge. In use, each of thesurgical stapling instruments involves the gripping of tissue to befastened, the ejecting of individual staples, the forcing of staplesthrough the gripped tissue and the closing and/or forming of the staplesagainst the staple forming depressions of the anvil.

A common issue in transecting tissue and/or in anastomosis procedures,employing any one of the surgical stapling instruments disclosed above,is the balance between anastomotic strength and the degree of hemostasisachievable. It is known to include different size staples in a surgicalstapling apparatus having a constant gap (i.e. a uniform distance)between an anvil and a staple cartridge.

SUMMARY

The present disclosure is directed towards surgical stapling instrumentsconfigured to effectuate an improved balance between the anastomoticstrength and the degree of hemostasis at the tissue interface. Inparticular, embodiments of the present disclosure include surgicalfasteners of different sizes. Further still, the distance between ananvil member and a staple cartridge (i.e. the gap) varies from acenterline of the staple cartridge to an outer edge of the staplecartridge. Preferably, the gap is greater at the outer edge of thecartridge in comparison to the gap at the centerline. This can beachieved by either varying the contour (i.e. profile) of the staplecartridge and/or the anvil member. Combining the different sizes ofsurgical fasteners with the varying gap between the anvil member and thestaple cartridge improves the anastomotic strength and the degree ofhemostasis at the tissue interface.

According to one aspect of the disclosure, the surgical staplinginstrument includes a first structure defining having an anvil memberoperatively associated therewith, and a second structure defining astaple cartridge operatively associated therewith. The staple cartridgehas a tissue contacting surface with a stepped cross-sectional profile.The tissue contacting surface of the staple cartridge also includes aplurality of retention slots formed therein for retaining a surgicalfastener. During operation of the surgical stapling instrument, theanvil member and the staple cartridge can be approximated relative toone another.

The stepped tissue contact surface of the staple cartridge defines aplurality of tissue contacting surfaces each having a different height.In one embodiment, the stepped tissue contacting surface of thecartridge includes an inner tissue contacting surface having a height,an intermediate tissue contacting surface having a height less than theheight of the inner tissue contacting surface, and an outer tissuecontacting surface having a height less than the height of theintermediate tissue contacting surface.

The inner, intermediate, and outer tissue contacting surfaces eachinclude at least one row of retention slots formed therein. A pluralityof surgical fasteners is disposed, one each, in each retention slot.Each surgical fastener includes a backspan and a pair of descendinglegs.

The surgical fasteners retained in the retention slots formed in theinner tissue contacting surface have a first leg length, the surgicalfasteners retained in the retention slots formed in the intermediatetissue contacting surface have a second leg length, and the surgicalfasteners retained in the retention slots formed in the outer tissuecontacting surface have a third leg length. In one embodiment, thesurgical fasteners retained in the retention slots formed in the innertissue contacting surface have a leg length of about 2.3 mm, while thesurgical fasteners retained in the retention slots formed in theintermediate tissue contacting surface have a leg length of about 3.5mm, and the surgical fasteners retained in the retention slots formed inthe outer tissue contacting surface have a leg length of about 4.1 mm.

It is envisioned that the surgical stapling instrument can be acircular-type surgical stapling instrument wherein the anvil member andthe staple cartridge can be annular. In one embodiment, the plurality oftissue contacting surfaces decreases in height in a radially outwarddirection. Accordingly, the inner tissue contacting surface is closestto the center and the outer tissue contacting surface is furthest fromthe center of the annular staple cartridge. Moreover, surgical fastenershaving relatively short leg lengths are retained in the retention slotsclosest to the center of the annular staple cartridge while surgicalfasteners having relatively longer leg lengths are retained in theretention slots furthest from the center of the annular staplecartridge.

It is further envisioned that the surgical stapling instrument can be alinear-type surgical stapling instrument wherein the anvil member andthe staple cartridge are linear. In these instruments, the staplecartridge and/or the anvil member may define a knife cut line.Accordingly, the plurality of tissue contacting surfaces decreases inheight in a direction orthogonally outward from the knife cut line. Inparticular, the inner tissue contacting surface is closest to the knifecut line while the outer tissue contacting surface is furthest from theknife cut line. In addition, surgical fasteners having relatively shortleg lengths are retained in the retention slots closest to the knife cutline while surgical fasteners having relatively longer leg lengths areretained in the retention slots furthest from the knife cut line.

It is envisioned that the anvil member can have a tissue contactingsurface with a stepped cross-sectional profile including a plurality oftissue contacting surfaces, wherein each tissue contacting surface has adifferent height. In addition, each one of the plurality of tissuecontacting surfaces can include at least one annular and/or linear rowof surgical fastener forming depressions formed therein.

In one embodiment, the anvil member can have a tissue contacting surfacewhich is shaped (i.e. stepped) to complement the stepped tissuecontacting surface of the staple cartridge. In another embodiment, theanvil member can have a tissue contacting surface which is stepped whilethe tissue contacting surface of the staple cartridge is substantiallyplanar. In yet another embodiment, the anvil member can have a tissuecontacting surface which is shaped to substantially complement thestepped tissue contacting surface of the staple cartridge (i.e. thedepths of the tissue contacting surfaces of the stepped anvil member arenot equal to the heights of the individual tissue contacting surfaces ofthe tissue contacting surface of the staple cartridge). In still anotherembodiment, the anvil member can have a tissue contacting surface whichis stepped to mirror the tissue contacting surface of the staplecartridge (i.e. the depths of individual tissue contacting surfaces ofthe tissue contacting surface of the anvil member are substantiallyequal to the depths of the individual tissue contacting surfaces of thestaple cartridge).

In other embodiments of the present disclosure, a surgical staplinginstrument includes an operative tool disposed at one end thereof. Theoperative tool includes an anvil member and a staple cartridge. Thestaple cartridge may be included in a disposable surgical staplingapparatus or in a reusable surgical stapling apparatus. Further still, areplaceable loading unit may be located in either the disposable or thereusable surgical stapling apparatus. In one embodiment, the replaceableloading unit includes a staple cartridge, while an alternate embodimentof the replaceable loading unit includes a staple cartridge and an anvilmember. In particular, the staple cartridge includes a plurality ofsurgical fasteners disposed in rows of retention slots. The surgicalfasteners may have different leg lengths wherein a plurality of surgicalfasteners having substantially the same leg length is disposed in a row.A number of fastener ejection members are disposed in the staplecartridge wherein each fastener ejection member includes a plurality ofstaple pushers for ejecting the surgical fasteners in cooperation withan actuation mechanism. The staple pushers of the fastener ejectionmember each have a shape that generally corresponds to the shape of thestaple pockets of the anvil member and the retention slots of the staplecartridge.

The staple cartridge may include an angled tissue contacting surfacethat peaks at a centerline of the staple cartridge and tapers towardsouter walls of the staple cartridge. Alternatively, the tissuecontacting surface of the staple cartridge may have a surface that isparallel with the bottom surface of the staple cartridge or parallel toa plane defined by the backspans of surgical fasteners disposed in aselected row. The parallel surface of the tissue contacting surface hasa width dimension that is sufficient to accommodate at least one row ofsurgical fasteners. The staple cartridge may include a knife channel.

In cooperation with the presently disclosed staple cartridge, the anvilmember may include a planar tissue contacting surface that issubstantially parallel to the bottom surface of the staple cartridge orparallel to a plane defined by the backspans of surgical fastenersdisposed in a selected row. In the alternative, the tissue contactingsurface of the anvil member may be angled in an opposed manner to theangle of the tissue contacting surface of the staple cartridge. Furtherstill, the tissue contacting surface of the anvil member may have aplanar surface that is substantially parallel to the bottom surface ofthe staple cartridge or parallel to a plane defined by the backspans ofsurgical fasteners disposed in a selected row and tapered surfaces thatdefine angles opposite to the angles defined by the tissue contactingsurface of the staple cartridge. The parallel surfaces of the anvilmember have a width dimension that corresponds to a width dimension ofthe parallel surface of the staple cartridge.

It is further contemplated that one embodiment of the surgical staplingapparatus includes structures for supplemental sealing of the fastenedlayers of tissue. In one embodiment, the surgical stapling apparatusincludes a wound closure assembly having a reservoir and a supply line.The reservoir is adapted for storing a quantity of a wound closurematerial and is fluidly coupled to the staple cartridge via the supplyline for delivering amounts of the wound closure material to theplurality of retention slots.

In yet another embodiment of the presently disclosed surgical staplingapparatus, the staple cartridge may include a planar surface proximate acenterline of the staple cartridge and an arcuate surface adjacent tothe planar surface. The arcuate surface extends outwards from thecenterline and downwards towards the base of the staple cartridgedefining a concave configuration with respect to the base of the staplecartridge. Each of the surfaces includes at least one row of retentionslots and defines a tissue contacting surface. In addition, thisembodiment of the staple cartridge includes a plurality fastenerejection members and a plurality of surgical fasteners. Tips of theunfired surgical fasteners may be positioned beneath the arcuate andplanar surfaces or may extend into the retention slots wherein the tipsare substantially flush with the tissue contacting surface. Thisembodiment of the staple cartridge may be combined with an anvil memberhaving a planar tissue contacting surface that cooperates with thetissue contacting surface of the staple cartridge to position layers oftissue therebetween and form completed surgical fasteners.Alternatively, an anvil member may have a planar surface correspondingin width to the planar surface of the staple cartridge and curvatesurfaces that have the same curvature as the arcuate surfaces of thestaple cartridge in an opposed direction. The staple cartridge mayinclude a knife channel that is located along the centerline of thestaple cartridge.

In a further embodiment of the presently disclosed surgical staplingapparatus, the staple cartridge may include first and second planarsurfaces, wherein each planar surface includes at least one row ofretention slots. The first and second planar surfaces are substantiallyparallel with a bottom surface of the staple cartridge and with eachother, but are vertically spaced apart such that there are not coplanarwith each other. As in the previous embodiments, the staple cartridgeincludes a plurality of fastener ejection members and a plurality ofsurgical fasteners. A first gap is defined between a planar tissuecontacting surface of an anvil member and the first planar surface ofthe staple cartridge and a second gap is defined between the planartissue contacting surface of the anvil member and the second planarsurface. The staple cartridge may include a knife channel that islocated along the centerline of the staple cartridge. Alternatively, ananvil member having a complementary surface configuration may be used incombination with the staple cartridge, wherein the spacing between thesecond planar surface of the staple cartridge and a correspondingsurface of the anvil member defines a gap that is greater than thesecond gap.

In a further embodiment of the presently disclosed surgical staplingapparatus, a staple cartridge is provided having a plurality of fastenerejection members and a plurality of surgical fasteners. The staplecartridge includes a planar surface opposed to a bottom surface. Afiller layer is positioned atop the planar surface. The filler layer maybe formed from a buttress material. The filler layer is generallytriangular in shape and extends downwards and outwards from a centerlineof the staple cartridge such that its maximum height is proximate to thecenterline. An anvil member having a planar surface may be used incooperation with the staple cartridge for forming completed surgicalfasteners. Alternatively, an anvil member having a tapered (i.e. angled)surface that complements the filler layer may be used. The staplecartridge may include a knife channel.

An alternate embodiment of the presently disclosed surgical staplingapparatus includes a staple cartridge and an anvil member. The staplecartridge includes a plurality of surgical fasteners and a plurality offastener ejection members. A top plate extends between inner and outerwalls of the staple cartridge and is a planar structure that issubstantially parallel to a bottom surface of the staple cartridge. Avertical member abuts the inner wall. Vertically spaced from the topplate is a cross member that is flexibly attached to the verticalmember. A top surface of the cross member defines a tissue contactingsurface in opposition to a tissue contacting surface of the anvilmember. During approximation and/or formation of surgical fasteners, thecross member flexes such that the gap between the tissue contactingsurfaces is at a minimum near the centerline of the staple cartridge anda maximum near the outer wall of the staple cartridge. The staplecartridge may include a knife channel. Alternatively, the anvil membermay include tapered surfaces that define the tissue contacting surface,wherein the tapered surfaces extend outwards and upwards from thecenterline of the staple cartridge such that the anvil member has itsmaximum thickness near the centerline and its minimum thickness nearouter edges of the anvil member.

In an additional embodiment of the presently disclosed surgical staplingapparatus, a substantially planar anvil member and a stepped staplecartridge are disclosed. In this embodiment, the staple cartridgeincludes a plurality of stepped surfaces each of which is substantiallya planar structure. Each stepped surface of the staple cartridge isconfigured for contacting tissue and includes a plurality of retentionslots. Each retention slot is adapted for receiving a surgical fastenertherein. Similar to the previously disclosed embodiments, the surgicalfasteners in one surface may have a leg length that is different fromthe leg length of the surgical fasteners in an adjacent surface. Thetissue contacting (i.e. stepped surfaces) surfaces may be arranged intwo linear rows that are separated by a knife channel. The tissuecontacting surfaces in each row are parallel to one another, but are notcoplanar with each other thereby defining the stepped arrangement of thetissue contacting surfaces. The transition from one tissue contactingsurface to the adjacent tissue contacting surface is an angled wallsurface.

All of the presently disclosed embodiments of the surgical staplinginstrument provide a variable pressure gradient (i.e. load profile) tothe layers of tissue that are joined together with the surgicalfasteners. Therefore, the layers of tissue that are proximate to thecenter of the surgical stapling instrument (i.e. center of the staplecartridge) are subjected to higher compressive forces (i.e. loads),thereby forming thinner layers of tissue as compared to layers of tissuethat are further away from the center of the surgical staplinginstrument. Since the layers of tissue nearest the center of thesurgical stapling instrument can be compressed more, a smaller sizedsurgical staple or fastener can be used to mechanically suture (i.e.fasten) the transected layers of tissue. Further still, providing agradual compression gradient to the layers of tissue to be joined, mayresult in a higher degree of hemostasis. Due to the contoured shape ofthe staple cartridge, the layers of tissue can be compressed more at thecenter of the surgical stapling instrument, because tissue can translate(i.e. move) from a region of relatively high pressure (i.e. at thecenter) to a region of relatively low pressure (i.e. at the edges) asthe anvil member is moved relative to the staple cartridge, therebydefining the pressure gradient.

In a further aspect of the present disclosure, a staple cartridge for asurgical stapling apparatus comprises a first tissue contacting surfaceand a second tissue contacting surface. The first tissue contactingsurface and the second tissue contacting surface are not co-planar. Athird surface generally extends between the first tissue contactingsurface and the second tissue contacting surface and an angle is definedbetween the third surface and at least one of the first or second tissuecontacting surfaces. A plurality of first retention slots are defined inthe first tissue contacting surface and a plurality of second retentionslots are defined in the second tissue contacting surface. Eachretention slot is configured for housing a staple therein.

The cartridge may have staples having a first leg length in the firstretention slots and staples having a second leg length in the secondretention slots, wherein the second leg length is different from thefirst leg length. The cartridge may be releasably attached to a body ofthe surgical apparatus, or may be part of a detachable disposableloading unit.

A knife channel desirably extends longitudinally along the cartridge.The first tissue contacting surface is desirably adjacent the knifechannel. In certain preferred embodiments, the staples with the firstleg length, which have leg lengths smaller than the staples with thesecond leg length, are disposed adjacent the knife channel.

The first tissue contacting surface may be substantially parallel to thesecond tissue contacting surface.

In a further aspect of the present disclosure, a surgical staplingapparatus comprises a handle portion, a body portion extending distallyfrom the handle portion and defining a longitudinal axis, and a toolassembly at a distal end of the body portion. The tool assembly includesa cartridge having a first tissue contacting surface and a second tissuecontacting surface. The first tissue contacting surface and the secondtissue contacting surface are not co-planar. A third surface generallyextends between the first tissue contacting surface and the secondtissue contacting surface. An angle is defined between the third surfaceand at least one of the first or second tissue contacting surfaces. Aplurality of first retention slots are defined in the first tissuecontacting surface and a plurality of second retention slots are definedin the second tissue contacting surface. Each retention slot isconfigured for housing a staple therein. The tool assembly of thesurgical stapling apparatus desirably includes an anvil member having asurface for contacting tissue and a number of staple forming depressionsdefined in the surface of the anvil member. The surface of the anvilmember is disposed in opposition to the first tissue contacting surfaceand the second tissue contacting surface. The surface of the anvilmember and the first tissue contacting surface define a first gap andthe surface of the anvil member and the second tissue contacting surfacedefine a second gap. The first gap has a different dimension from thesecond gap. In certain preferred embodiments, the first gap is less thanthe second gap. The staples with the smaller length are desirablydisposed adjacent a centerline of the staple cartridge.

In another aspect of the present disclosure, a staple cartridge for asurgical stapling apparatus comprises a first tissue contacting surfaceand a second tissue contacting surface. The first tissue contactingsurface and the second tissue contacting surface are not co-planar. Athird surface generally extends between the first tissue contactingsurface and the second tissue contacting surface. The third surface is anon-planar surface. A plurality of first retention slots are defined inthe first tissue contacting surface and a plurality of second retentionslots are defined in the second tissue contacting surface. Eachretention slot is configured for housing a staple therein.

The cartridge may have staples having a first leg length in the firstretention slots and staples having a second leg length in the secondretention slots, wherein the second leg length is different from thefirst leg length. The cartridge may be releasably attached to a body ofthe surgical apparatus, or may be part of a detachable disposableloading unit.

A knife channel desirably extends longitudinally along the cartridge.The first tissue contacting surface is desirably adjacent the knifechannel. In certain preferred embodiments, the staples with the firstleg length, which have leg lengths smaller than the staples with thesecond leg length, are disposed adjacent the knife channel.

The first tissue contacting surface may be substantially parallel to thesecond tissue contacting surface.

The presently disclosed surgical stapling instruments, together withattendant advantages, will be more clearly illustrated below by thedescription of the drawings and the

DETAILED DESCRIPTION OF THE EMBODIMENTS

Other objects and features of the present disclosure will becomeapparent from consideration of the following description taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the presently disclosed surgical stapling apparatus aredescribed herein with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of a surgical stapling instrumentconstructed in accordance with the present disclosure;

FIG. 2 is a schematic cross-sectional side elevational view of thedistal end portion of the surgical stapling instrument of FIG. 1, astaken through 2-2 of FIG. 1;

FIG. 2A is a perspective view of a surgical fastener in accordance withan embodiment of the present disclosure;

FIG. 3A is an enlarged schematic representation of the indicated area ofFIG. 2, illustrating tissue contacting surfaces in accordance with analternate embodiment of the present disclosure;

FIG. 3B is an enlarged schematic representation of the indicated area ofFIG. 2, illustrating tissue contacting surfaces in accordance withanother embodiment of the present disclosure;

FIG. 3C is an enlarged schematic representation of the indicated area ofFIG. 2, illustrating tissue contacting surfaces in accordance with stillanother embodiment of the present disclosure;

FIG. 3D is an enlarged schematic representation of the indicated area ofFIG. 2, illustrating tissue contacting surfaces in accordance with afurther embodiment of the present disclosure;

FIG. 4 is a perspective view of an alternative surgical staplinginstrument constructed in accordance with the present disclosure;

FIG. 5 is a perspective view of yet another surgical stapling instrumentconstructed in accordance with the present disclosure;

FIG. 6 is a perspective view of still another surgical staplinginstrument constructed in accordance with the present disclosure;

FIG. 6A is a perspective view of a portion of an anvil member of FIG. 6;

FIG. 7 is a schematic cross-sectional side elevational view of thedistal end portion of the surgical stapling instruments of FIGS. 4-6, astaken through 7-7 of each of FIGS. 4-6;

FIG. 7A is a schematic cross-sectional side elevational view of analternate embodiment of the distal portion of the surgical staplinginstrument of FIG. 6

FIG. 8 is a perspective view of a staple cartridge according to anotherembodiment of the present disclosure;

FIG. 9A is a cross-sectional end view of the staple cartridge of FIG. 8showing a first arrangement of surgical fasteners;

FIG. 9B is a cross-sectional end view of the staple cartridge of FIG. 8showing a second arrangement of surgical fasteners;

FIG. 9C is an alternate embodiment of the staple cartridge of FIG. 8showing a second arrangement of surgical fasteners and an alternateembodiment of an anvil member;

FIG. 10 is an alternate embodiment of the staple cartridge of FIG. 9Aillustrating a second embodiment of the surgical fasteners;

FIG. 11 is an alternate embodiment of an anvil member and the staplecartridge of FIG. 10;

FIG. 12 is a further embodiment of the staple cartridge of FIG. 8;

FIG. 13 is another embodiment of the anvil member and the staplecartridge of FIG. 12;

FIG. 14 is another embodiment of the staple cartridge and anvil memberof FIG. 8;

FIG. 15 is alternate embodiment of an anvil member with the staplecartridge of FIG. 14;

FIG. 16A is a cross-sectional side elevation view of a tissue interfacefollowing the firing of a conventional surgical stapling instrument;

FIG. 16B is a cross-sectional side elevational view of the resultingtissue interface following the firing of surgical stapling instrument ofFIGS. 7 and 10-15;

FIG. 17A is a cross-sectional end view of another embodiment of thestaple cartridge of FIG. 8 showing a first arrangement of surgicalfasteners;

FIG. 17B is an alternate embodiment of the staple cartridge of FIG. 17Ashowing a second arrangement of surgical fasteners;

FIG. 17C is an alternate embodiment of an anvil member and the staplecartridge of FIG. 17A;

FIG. 17D is an alternate embodiment of an anvil member and the staplecartridge of FIG. 17B;

FIG. 17E is a further embodiment of the staple cartridge of FIG. 17A;

FIG. 17F is an alternate embodiment of an anvil member and the staplecartridge of FIG. 17E;

FIG. 18A is a cross-sectional end view of a further embodiment of thestaple cartridge of FIG. 8;

FIG. 18B is an alternate embodiment of an anvil member and the staplecartridge of FIG. 18A;

FIG. 19A is a cross-sectional end view of a further embodiment of thestaple cartridge of FIG. 8 illustrating a shaped support member disposedon a tissue contacting surface of the staple cartridge and a shapedsupport member, in phantom, disposed on a tissue contacting surface ofthe anvil member;

FIG. 19B is an alternate embodiment of an anvil member and the staplecartridge of FIG. 19A;

FIG. 20A is a cross-sectional end view of another embodiment of thestaple cartridge of FIG. 7A;

FIG. 20B is a cross-sectional end view of an alternate embodiment of ananvil member and the staple cartridge of FIG. 20A;

FIG. 20C is a further embodiment of an anvil member and the staplecartridge of FIG. 20B;

FIG. 21A is a cross-sectional end view of another embodiment of thestaple cartridge of FIG. 8;

FIG. 21B is another embodiment of an anvil member and the staplecartridge of FIG. 21B;

FIG. 22A is a cross-sectional end view of a further embodiment of thestaple cartridge of FIG. 8 and a further embodiment of an anvil member;

FIG. 22B is an alternate embodiment of the staple cartridge and theanvil member of FIG. 22A;

FIG. 22C is a further embodiment of an anvil member with the staplecartridge of FIG. 22B;

FIG. 23 is a perspective view of another embodiment of the presentlydisclosed operative tool illustrating a staple cartridge and an anvilmember in an approximated position;

FIG. 24 is an enlarged perspective view of the operative tool of FIG. 23illustrating the relationship between tissue contacting surfaces of thestaple cartridge;

FIG. 25 is an exploded view of the operative tool showing a number ofstaples, a staple pusher, and a sled;

FIG. 26 is an enlarged perspective view of the section of detail in FIG.25 illustrating the leg lengths of the staples;

FIG. 27 is a perspective cross-sectional view of the operative tool ofFIG. 23 with the anvil member removed;

FIG. 28 is a cross-sectional view of the cartridge of FIG. 27 includingstaples having different leg lengths taken along section line 28-28;

FIG. 29 is a front cross-sectional view of the cartridge of FIG. 27taken along section line 29-29;

FIG. 30 is a front elevational view of the operative tool of FIG. 27;

FIG. 31 is a cross-sectional side elevational view of a tissue interfacefollowing the firing of operative tool shown in FIGS. 23-30; and

FIG. 32 is front cross-sectional view of an alternate embodiment of thecartridge shown in FIG. 29.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed surgical stapling instrumentswill now be described in detail with reference to the drawing figureswherein like reference numerals identify similar or identical elements.In the drawings and in the description which follows, the term“proximal”, as is traditional, will refer to the end of the surgicalstapling instrument which is closest to the operator while the term“distal” will refer to the end of the device which is furthest from theoperator.

The present disclosure relates to a staple cartridge and an anvil memberfor use in a disposable or re-usable surgical stapling apparatus. Thepresently disclosed staple cartridge and anvil member, as will bediscussed in detail hereinbelow, may be used with any of the surgicalstapling apparatus shown in FIG. 1, 4, 5, or 6. In addition, areplaceable loading unit may be located in either the disposable or thereusable surgical stapling apparatus. In one embodiment, the replaceableloading unit includes a staple cartridge, including any of the staplecartridges disclosed herein. Alternatively, the replaceable loading unitincludes the staple cartridge and an anvil member, including any of theanvil members disclosed herein. In combination with the disposable orthe reusable surgical stapling apparatus, the replaceable loading unitprovides improved flexibility of the respective surgical staplingapparatus in that the respective surgical stapling apparatus is readilyadaptable for different stapling procedures. In each of the embodimentsthat are hereinafter disclosed, staples or surgical fasteners disposedin the staple cartridge are arranged such that tips of the surgicalfasteners may be substantially flush with a tissue contacting surface ofthe staple cartridge. Alternately, the tips of the surgical fastenersmay be located above or below the tissue contacting surface.

Referring now in detail to FIGS. 1-2, in which like reference numeralsidentify similar or identical elements, a surgical stapling instrument,in accordance with a first embodiment of the disclosure, is generallydesignated as 100.

As seen in FIG. 1, surgical stapling instrument 100 includes a handleassembly 102 having at least one pivotable actuating handle member 103,and further includes advancing means 105. Extending from handle assembly102, there is provided a tubular body portion 104 which may beconstructed so as to have a curved shape along its length. Tubular bodyportion 104 terminates in a fastener ejection assembly 106 having acircular staple cartridge 118 including a tissue contacting surface 121disposed at a distal end thereof. An anvil shaft 110 operatively couplesan anvil assembly 108 to handle assembly 102. Anvil assembly 108 isrepositionable from a location where it is in close cooperativealignment with staple cartridge 118 to a location where it is spacedapart from staple cartridge 118. Anvil assembly 108 includes an anvilhead 109. Further still, surgical stapling instrument 100 may include awound closure assembly 50. Wound closure assembly 50 includes at leastone storage device or reservoir 52 and at least one supply line 54.Supply line 54 fluidly couples reservoir 52 to anvil shaft 110, whereinanvil shaft includes at least one opening 56 for dispensing woundclosure material “W”. By providing wound closure material “W” incombination with surgical fasteners, the bond formed between the layersof tissue has improved strength.

As seen in FIG. 2, tissue contacting surface 121 is stepped including anouter tissue contacting surface 121 a, an intermediate tissue contactingsurface 121 b, and an inner tissue contacting surface 121 c. Each tissuecontacting surface 121 a-121 c has a different height from one anotheras measured from a point 131 on a bottom surface of a staple pusher orfastener ejection member 130. Point 131 is proximal to a shaft 111 in aregion where the bottom surface of fastener ejection member 130 issubstantially planar. Specifically, tissue contacting surfaces 121 a-121c are planar structures that are substantially parallel to one another,but are not co-planar (i.e. stepped) with one another. In addition, eachtissue contacting surface 121 a-c defines a planar axis that extendsthrough the respective tissue contacting surface 121 a-c. A first wallsurface interconnects tissue contacting surfaces 121 a and 121 b, whilea second wall surface interconnects tissue contacting surfaces 121 b and121 c. The first and second wall surfaces are planar structures whereineach wall surface defines a planar axis. In one embodiment, the planaraxes of the wall surfaces are orthogonal to the planar axes of tissuecontacting surfaces 121 a-c.

Inner tissue contacting surface 121 c has the greatest height, outertissue contacting surface 121 a has the least height, and intermediatetissue contacting surface 121 b has a height between the heights ofouter and inner tissue contacting surfaces 121 a, 121 c. While tissuecontacting surfaces 121 a-121 c are shown as increasing in height fromouter tissue contacting surface 121 a to inner tissue contacting surface121 c (i.e. radially inward), it is within the scope of the presentdisclosure that the heights of each tissue contacting surface can varydepending on the particular surgical procedure. For example, tissuecontacting surfaces 121 a-121 c can increase in height in a radiallyoutward direction, the intermediate tissue contacting surface 121 b canbe the highest or the lowest tissue contacting surface, or at least twoof tissue contacting surfaces 121 a-121 c can have the same height.

In one embodiment, each tissue contacting surface 121 a-121 c includes arespective annular row 119 a-119 c of retention slots 123 formedtherein. Each retention slot 123 of annular rows 119 a-119 c isconfigured and dimensioned to retain a staple or surgical fastener 125therein. As shown in FIG. 2A, each surgical fastener 125 includes abackspan 27 and a pair of depending legs 25. Each leg 25 forms a rightangle in relation to backspan 27. In one embodiment, each annular row119 a-119 c of slots 123 includes a respective surgical fastener 125a-125 c having its own characteristic features.

As seen in FIG. 2, legs 25 a of surgical fasteners 125 a have a firstleg length, legs 25 b of surgical fasteners 125 b have a second leglength, and legs 25 c of surgical fasteners 125 c have a third leglength. In particular, surgical fasteners 125 a-125 c increase in heightin a radially outward direction. In one embodiment, legs 25 c ofsurgical fasteners 125 c have a leg length of about 2.3 mm, legs 25 b ofsurgical fasteners 125 b have a leg length of about 3.5 mm, and legs 25a of surgical fasteners 125 a have a leg length of about 4.1 mm. Assuch, inner tissue contacting surface 121 c has the greatest height andretains surgical fasteners 125 c having the shortest leg lengths, andouter tissue contacting surface 121 a has the least height and retainssurgical fasteners 125 a having the longest leg lengths. Having tissuecontacting surface 121 step progressively downward at intermediatetissue contacting surface 121 b and then again at outer tissuecontacting surface 121 a results in the formation of surgical fasteners125 b and 125 c, respectively. It is envisioned and within the scope ofthe present disclosure that any number of arrangements are possible.

While a single annular row 119 a-119 c of retention slots 123 is shownfor each tissue contacting surface 121 a-121 c, it is envisioned andwithin the scope of the present disclosure that each tissue contactingsurface 121 a-121 c can include multiple annular rows of retentionslots.

As seen in FIG. 2, a fastener ejection assembly 106 of surgical staplinginstrument 100 includes fastener ejection member 130 disposed withinstaple cartridge 118. Fastener ejection member 130 includes a proximalportion 132 having a generally frusto-conical shape and a distal portiondefining concentric rings of peripherally spaced staple pushers 134 a-c,each one of which is received within a respective staple retention slot123 and is cooperative with its respective surgical fastener 125 a-cdisposed in annular rows 119 a-c. In one embodiment, it is envisionedthat proximal portion 132 of fastener ejection member 130 is configuredand dimensioned to be contacted by a distal end of a driver tube 138.Hence, upon advancing fastener ejection member 130 by advancing drivertube 138, staple pushers 134 a-c will pass further into retention slots123 thereby pushing surgical fasteners 125 contained therein axiallyoutward.

In an alternate embodiment, staple pushers 134 a-c of fastener ejectionmember 130 have different heights for cooperating with different sizedsurgical fasteners. In particular, staple pushers 134 a-c are sized suchthat when surgical fasteners 125 a-c are disposed in their respectiveannular rows 119 a-c, tips of surgical fasteners 125 a-c are locatedsubstantially in the same plane despite the difference in leg lengthsbetween each row of surgical fasteners.

Surgical stapling instrument 100 (FIG. 1) includes circular anvilassembly 108 having anvil head 109 and anvil shaft 110 extending from aproximal end thereof and adapted to engage shaft 111 extending distallyfrom staple cartridge 118. Anvil head 109 includes an annular anvilmember 112 disposed at a proximal end thereof, wherein anvil member 112includes at least one, row of fastener forming depressions 114 formedcircumferentially thereabout. In one embodiment, surgical staplinginstrument 100 includes three laterally spaced rows of fastener formingdepressions 114 formed circumferentially thereabout. Each fastenerforming depression 114 is in registration with a corresponding retentionslot 123.

While anvil member 112 is shown in FIG. 2 as having a substantiallyplanar tissue contacting surface, it is envisioned and within the scopeof the present disclosure for surgical stapling instrument 100 to have anumber of alternate configurations. For example, as seen in FIG. 3A,anvil member 112 a can have a tissue contacting surface, includingsurfaces 116 a-116 c, which is shaped (i.e. stepped) to complementstepped tissue contacting surface 121 of staple cartridge 118 or, asseen in FIG. 3B, anvil member 112 b can have a tissue contactingsurface, including surfaces 116 a-c, which is stepped while tissuecontacting surface 121 of staple cartridge 118 is substantially planar.In addition, for example, as seen in FIG. 3C, anvil member 112 c canhave one row of staple pockets 114 b that extends a greater distancethan staple pockets 114 a or 114 c into anvil member 112 c foraccommodating surgical fasteners having a longer leg length or, as seenin FIG. 3D, anvil member 112 d can have a tissue contacting surface,including surfaces 116 a-c, which is stepped to mirror tissue contactingsurface 121 of staple cartridge 118 (i.e. the depths of individualtissue contacting surfaces of the tissue contacting surface of anvilmember 112 d are substantially equal to the depths of the individualtissue contacting surfaces 121 a-121 c of staple cartridge 118).

The sizes of surgical fasteners 125 a-125 c are selected and intendedfor use in gastric firings typically required in bariatric procedures.However, it is envisioned and within the scope of the present disclosurethat the sizes of surgical fasteners 125 a-125 c selected can be chosenfor performance in different types of tissue, such as, for example, thecolon, bowels, lungs, the bronchus, pulmonary vessels, the liver, andthe like.

In operation, surgical stapling instrument 100 is positioned within atubular organ in the body of the patient and the ends of the organ to bejoined are positioned in a gap between staple cartridge 118 and anvilassembly 108. As is conventional, the ends of the organ may be securedaround anvil shaft 110 by a purse string suture prior to approximationof anvil assembly 108 to staple cartridge 118. Surgical staplinginstrument 100 is then approximated and fired. An example of a surgicalstapling apparatus and methods for its use are disclosed in U.S. Pat.No. 5,915,616, currently assigned to Tyco Healthcare Group LP, theentire contents of which is incorporated herein by reference.

Turning now to FIGS. 4 and 7, a surgical stapling instrument, of thegastrointestinal anastomosis type for performing surgical anastomoticstapling, in accordance with another embodiment of the disclosure, isgenerally designated as 200. Surgical stapling instrument 200 includes afirst handle 202 having a jaw 203 defining a staple cartridge receivingsection extending from a distal end thereof, a staple cartridge 204receivable in jaw 203, a second handle 206 having a jaw 205 defining ananvil member receiving section extending from a distal end thereof, andan anvil member 208 operatively associated with jaw 205. First andsecond handles 202, 206 are configured such that staple cartridge 204 issubstantially aligned with anvil member 208.

As seen in FIG. 7, staple cartridge 204 includes a stepped tissuecontacting surface 121 including an outer tissue contacting surface 121a, an intermediate tissue contacting surface 121 b, and an inner tissuecontacting surface 121 c, each of which has a different height from oneanother as measured from a point 231 that is located on a bottom surfaceof staple cartridge 204, wherein point 231 exists along a centerline ofstaple cartridge 204. Tissue contacting surfaces 121 a-121 c are planarstructures that are substantially parallel to one another, but are notco-planar with one another. For example, tissue contacting surfaces 121a-121 c, as shown in FIG. 7, can decrease in height in a directionorthogonally outward from knife track 222. In embodiments that do notinclude knife track 222, tissue contacting surfaces 121 a-c decrease inheight in a direction orthogonally outward from a centerline of staplecartridge 204.

Each tissue contacting surface 121 a-121 c includes a respective linearrow 119 a-119 c of retention slots 123 formed therein. Each retentionslot 123 of linear rows 119 a-119 c is configured and dimensioned toretain a surgical fastener 125 therein. Each linear row 119 a-119 c ofslots 123 includes a respective surgical fastener 125 a-125 c having itsown characteristic features.

As seen in FIG. 7, legs 25 a of surgical fasteners 125 a have a firstleg length of about 4.1 mm, legs 25 b of surgical fasteners 125 b have asecond leg length of about 3.5 mm, and legs 25 c of surgical fasteners125 c have a third leg length of about 2.3 mm. In particular, surgicalfasteners 125 a-125 c increase in height in an orthogonally outwarddirection relative towards optional knife track 222. Knife track 222 isdisposed along a centerline of staple cartridge 204, 310, or 412 and isadapted for slidably receiving an optional knife (not shown). Havingtissue contacting surface 121 step progressively downward atintermediate tissue contacting surface 121 b and then again at outertissue contacting surface 121 a results in the formation of surgicalfasteners 125 b and 125 c, respectively. It is envisioned and within thescope of the present disclosure that any number of arrangements arepossible.

In operation, surgical stapling instrument 200 is fired similarly to andin accordance with other known surgical stapling instruments. An exampleof a surgical stapling apparatus and methods for its use are isdisclosed in U.S. Pat. No. 6,202,914, currently assigned to TycoHealthcare Group LP, the entire contents of which is incorporated hereinby reference.

Referring additionally to FIG. 16B, following the firing of surgicalstapling instrument 200, the resulting tissue interface is seen incross-section. Accordingly, some or all of surgical fasteners 125 a-125c serve to hold tissues “A” and “B” to one another while surgicalfasteners 125 c also provide the hemostasis.

While surgical stapling instrument 200 is a linear-type surgicalstapler, it is envisioned and within the scope of the presentdisclosure, that surgical stapling instrument 200 can include a tissuecontacting surface having a cross-sectional profile for at least one ofthe anvil member and the staple cartridge which is substantially similarto the tissue contacting surfaces of the anvil member and the staplecartridge of surgical stapling instrument 100, as shown in FIGS. 3A-3D.

Turning now to FIGS. 5 and 7, a surgical stapling instrument, of thelaparoscopic type for performing surgical anastomotic stapling, inaccordance with another embodiment of the disclosure, is generallydesignated as 300. Surgical stapling instrument 300 includes a handle302, an operative tool 306, and an elongated shaft 304 forinterconnecting operative tool 306 to handle 302. In general, operativetool 306 is designed to clamp over and then to staple and divide tissueheld therein. Accordingly, as seen in FIG. 5, operative tool 306 is apair of opposed jaws including an anvil member 308 and a staplecartridge 310 pivotally coupled to one another.

Staple cartridge 310 of surgical stapling instrument 300 includes astepped tissue contacting surface 121 similar to tissue contactingsurface 121 of staple cartridge 204 of surgical stapling instrument 200.Accordingly, reference is made to FIG. 7 and the above detaileddiscussion of tissue contacting surface 121 of staple cartridge 204 foran illustration and a discussion of tissue contacting surface 121 ofstaple cartridge 310 of surgical stapling instrument 300.

In operation, surgical stapling instrument 300 is fired similarly to andin accordance with other known surgical stapling instruments. For adetailed discussion of the approximation and firing of surgical staplinginstrument 300, reference is made to commonly assigned U.S. Pat. No.5,865,361, currently assigned to Tyco Healthcare Group LP, the entirecontents of which is incorporated herein by reference.

Following the firing of surgical stapling instrument 300 the resultingtissue interface, as seen in cross-section, is substantially similar tothe resulting tissue interface, as seen in cross-section, following thefiring of surgical stapling instruments 100 and 200. Accordingly, asseen in FIG. 16B, some or all of surgical fasteners 125 a-125 c serve tohold tissues “A” and “B” to one another while surgical fasteners 125 calso provide the hemostasis.

While surgical stapling instrument 300 is a linear-type surgical stapleras compared to surgical stapling instrument 100, it is envisioned andwithin the scope of the present disclosure, that surgical staplinginstrument 300 can include a tissue contacting surface having across-sectional profile for at least one of the anvil and the staplecartridge which is substantially similar to the tissue contactingsurfaces of the anvil and the staple cartridge of surgical staplinginstrument 100, as shown in FIGS. 3A-3D.

Turning now to FIGS. 6, 6A, 7, and 7A, a surgical stapling instrument,of the transverse anastomosis type for performing surgical anastomoticstapling, in accordance with yet another embodiment of the disclosure,is generally designated as 400. Surgical stapling instrument 400includes a handle 402, a barrel 404 extending from handle 402, and anarm 406 extending from the distal end of barrel 404. Surgical staplinginstrument 400 further includes an anvil member 408 orthogonally affixedto a distal end of arm 406 and a staple cartridge receiver 410operatively coupled to the distal end of barrel 404 for holding adisposable staple cartridge 412 thereon. Anvil member 408 is illustratedin further detail in FIG. 6A and includes a tissue contacting surface420 wherein tissue contacting surface 420 has a plurality of pockets 425that substantially align with retention slots 123 (FIG. 7). Cooperativealignment between pockets 425 and retention slots 123 form completedsurgical fasteners 125 upon actuation of the actuation mechanism insurgical stapling instrument 400.

Staple cartridge 412 of surgical stapling instrument 400 includes astepped tissue contacting surface 121 similar to tissue contactingsurface 121 of staple cartridge 204 of surgical stapling instrument 200.Accordingly, reference is made to FIG. 7 and the above detaileddiscussion of tissue contacting surface 121 of staple cartridge 204 foran illustration and a discussion of tissue contacting surface 121 ofstaple cartridge 412 of surgical stapling instrument 400. Further still,staple cartridge 412 may include knife track 222 for slidably receivinga knife (not shown) therein.

In a further embodiment of the present disclosure, staple cartridge 412′is illustrated in FIG. 7A and discussed in detail hereinafter. Staplecartridge 412′ is similar to staple cartridge 412, but only includesthree rows 119 a-c of retention slots 123 disposed between outer wallsof staple cartridge 412′. As in the previously discussed embodiment,each row 119 a-c includes a plurality of surgical fasteners whereinsurgical fasteners in row 119 a have a different leg length fromsurgical fasteners disposed in row 119 b, while surgical fastenersdisposed in row 119 c have a leg length that is different from at leastone of rows 119 a or 119 b. This embodiment of the staple cartridge doesnot include a knife track. The arrangement and interrelationship oftissue contacting surfaces 121 a-c is similar to that previouslydisclosed with reference to FIG. 7.

In operation, surgical stapling instrument 400 is fired similarly to andin accordance with other known surgical stapling instruments. For adetailed discussion of the approximation and firing of surgical staplinginstrument 400, reference is made to commonly assigned U.S. Pat. No.5,964,394, currently assigned to Tyco Healthcare Group LP, the entirecontents of which is incorporated herein by reference.

Following the firing of surgical stapling instrument 400 the resultingtissue interface, as seen in cross-section, is substantially similar tothe resulting tissue interface, as seen in cross-section, following thefiring of surgical stapling instruments 100-300. Accordingly, as seen inFIG. 16B, some or all of surgical fasteners 125 a-125 c serve to holdtissues “A” and “B” to one another while surgical fasteners 125 c alsoprovide the hemostasis.

While surgical stapling instrument 400 is a linear-type surgical stapleras compared to surgical stapling instrument 100, it is envisioned andwithin the scope of the present disclosure, that surgical staplinginstrument 400 can include a tissue contacting surface having across-sectional profile for at least one of the anvil and the staplecartridge which is substantially similar to the tissue contactingsurfaces of the anvil and the staple cartridge of surgical staplinginstrument 100, as shown in FIGS. 3A-3D.

While each of the surgical stapling instruments described above andshown herein are configured and adapted to fire surgical fasteners 125,it is envisioned and within the scope of the present disclosure, thattissue contacting surfaces of surgical instruments used in connectionwith applying two-part fasteners can also have stepped configurations asshown and described herein. A typical two-part surgical fastenerapplying instrument is shown and described in commonly assigned U.S.Pat. No. 5,573,169, currently assigned to Tyco Healthcare Group LP, theentire contents of which is incorporated herein by reference.

In one further embodiment of the present disclosure, as illustrated inFIGS. 8-10, surgical stapling apparatus 300 includes an operative tool506 disposed at one end of elongated shaft 304. Operative tool 506includes anvil member 308 and a staple cartridge 510. Staple cartridge510 may be included in a disposable surgical stapling apparatus or in areusable surgical stapling apparatus. In particular, staple cartridge510 includes a tissue contacting surface 520 having a plurality ofretention slots 523 disposed therein and arranged in rows that aresubstantially aligned with a longitudinal axis of staple cartridge 510.As seen in FIG. 8, each row of retention slots 523 is longitudinallyoffset from an adjacent row of retention slots. In particular, anoptional knife channel 530 is disposed along the longitudinal axis ofstaple cartridge 510 that is adapted for slidably receiving a knife (notshown).

Referring now to FIG. 9A, operative tool 506 is shown in cross-sectionand illustrates the several components included in staple cartridge 510.Anvil member 308 includes a substantially planar tissue contactingsurface 320 that is substantially parallel to a bottom surface 512 orparallel to a plane defined by the backspans of surgical fasteners 125a, 125 b, or 125 c. Staple cartridge 510 includes outer walls 514 havinga first height and inner walls 516 having a second height wherein thesecond height is greater than the first height. Tissue contactingsurface 520 is attached to inner walls 516 and to outer walls 514 anddefines an angle with respect to a plane that is orthogonal to innerwalls 516. Tissue contacting surface 520 defines a generally curved pathbetween outer walls 514 (i.e. generally convex or elliptical as viewedin cross-section). Additionally, a plurality of surgical fasteners 125a-c are disposed in staple cartridge 510 wherein each row of retentionpockets 523 includes a number of substantially identical surgicalfasteners (i.e. 125 a, 125 b, or 125 c). Similar to previousembodiments, legs 25 a-c of surgical fasteners 125 a-c have differentlengths. In this embodiment, surgical fasteners 25 a have a leg lengthof about 3.8 mm, surgical fasteners 25 b have a leg length of about 3.5mm, and surgical fasteners 25 c have a leg length of about 2.5 mm.

As seen in FIG. 9A, surgical fasteners 125 a-c are disposed in staplecartridge 510 such that surgical fasteners 125 c are proximate to outerwalls 514, surgical fasteners 125 a are disposed proximate to innerwalls 516, and surgical fasteners 125 b are disposed therebetween. Incooperation with the surgical fasteners of varying height, staplecartridge 510 includes fastener ejection members 540 that include staplepushers 542, 544, and 546 of differing heights. Staple pusher 542 hasthe greatest height dimension, staple pusher 546 has the least heightdimension, and staple pusher 544 has a height dimension therebetween. Inthis embodiment, surgical fasteners 125 a-c are arranged to cooperatewith staple pushers 546, 544, and 542 respectively. Fastener ejectionmember 540 is adapted for substantially vertical movement when itcooperatively engages with an actuation mechanism (not shown). Anexample of a suitable actuation mechanism is disclosed in U.S. Pat. No.5,865,361 as discussed with reference to previously disclosed surgicalstapling instrument 300.

As illustrated in FIG. 9A, fastener ejection member 540 includes staplepushers 542, 544, and 546 that are connected to each other by aconnecting member 548, such that all of the pusher plates translatesubstantially simultaneously through staple cartridge 510. In analternate embodiment, fastener ejection member 540′ includes pusherplates 542, 544, and 546 that are individually set within staplecartridge 510. In this embodiment, each row of staple pushers isindividually actuatable and independent of the other rows of staplepushers. Either embodiment of the fastener ejection member 540, 540′ maybe used in any of the disclosed staple cartridges. Fastener ejectionmember 540′ is illustrated in FIG. 9A and, for the sake of clarity, willnot be illustrated in other embodiments of the disclosed surgicalstapling apparatus.

In addition, staple cartridge 510 may include a plurality of stapleguides or channels 525, shown in phantom, that extend from an insidesurface of tissue contacting surface 520 towards fastener ejectionmember 540 or 540′. In particular, staple channels 525 extend towardsstaple pushers 542, 544, and 546, and may also vary in height accordingto their placement within staple cartridge 510. Each staple channel 525is substantially equal in width to a width of its corresponding staplepusher 542, 544, or 546. Staple channels 525, in cooperation withretention slots 523 form staple pockets and improve the stability ofsurgical fasteners 125 a-c, thereby minimizing lateral or rotationalmovement of surgical fasteners 125 a-c and consequently improving theformation of completed fasteners. Further still, staple channels 525typically have a shape that corresponds to the shape of staple pushers542, 544, and 546. For the sake of clarity, staple channels 525 are onlyillustrated in FIG. 9A, although staple channels 525 may be included inany of the disclosed embodiments of the staple cartridge.

Alternate embodiments of operative tool 506 are illustrated in FIGS. 9Band 9C. These alternate embodiments are identified as operative tool 506a and 506 b respectively. Referring initially to FIG. 9B, operative tool506 a includes substantially the same or similar components discussedhereinabove for operative tool 506 with the differences discussedhereinbelow. In contrast to operative tool 506 (FIG. 9A), surgicalfasteners 125 a-c of operative tool 506 a are arranged in staplecartridge 510 a such that surgical fasteners 125 a are proximate toouter walls 514, surgical fasteners 125 c are proximate to inner walls516, and surgical fasteners 125 b are disposed therebetween. Inaddition, operative tool 506 a includes tissue contacting surface 520 athat includes first and second surfaces 522 a and 524 a. Each of firstand second surfaces 522 a, 524 a has a width dimension sufficient toinclude at least one row of surgical fasteners. First surface 522 a issubstantially parallel to bottom surface 512, while second surface 524 adefines a substantially uniform angle. In particular, second surface 524a extends outwards and downwards from an outer edge of first surface 522a and defines the substantially uniform angle with respect to bottomsurface 512.

Turning now to FIG. 9C, operative tool 506 b includes staple cartridge510 a that was discussed in reference to FIG. 9B and anvil member 308 c.Anvil member 308 c includes tissue contacting surface 320 c. Inparticular, tissue contacting surface 320 c includes surfaces 322 c and324 c. Surface 324 c is substantially parallel to bottom surface 512 hasa width dimension that is substantially equal to the width dimensions ofthe first surfaces 522 a and knife channel 530, while each surface 322 csubstantial complements corresponding second surface 524 a. Thisarrangement between the surfaces of anvil member 308 c and tissuecontacting surface 520 a maintains a substantially uniform gap betweenthe surfaces from the centerline of operative tool 506 b to its outerwalls 514.

Alternatively, as shown in FIG. 10, surgical fasteners 125 a-c aredisposed in staple cartridge 510′ such that surgical fasteners 125 a areproximate to outer walls 514, surgical fasteners 125 c are disposedproximate to inner walls 516, and surgical fasteners 125 b are disposedtherebetween. Contrary to the previous embodiment, surgical fasteners125 a-c are arranged to cooperate with staple pushers 542, 544, and 546respectively. After a number of layers of body tissue are positionedbetween tissue contacting surfaces 320 and 520, the actuation mechanismis actuated for sequentially ejecting surgical fasteners 125 a-c throughretention slots 523 whereby interaction between surgical fasteners 125a-c and anvil member 308 forms completed surgical fasteners for joiningthe layers of body tissue.

When tissue contacting surface 320 of anvil member 308 is repositionedproximate to tissue contacting surface 520 of staple cartridge 510′, theamount of pressure applied to the layers of tissue disposed therebetweenvaries along a plane that is transverse to the longitudinal axis ofstaple cartridge 510′. Since the distance between tissue contactingsurfaces 320 and 520 is at a minimum in the region nearest inner walls516 (i.e. the centerline of staple cartridge 510′), a maximum pressureis applied to the layers of tissue disposed in this region. Conversely,the distance between tissue contacting surfaces 320 and 520 is at amaximum in the region near outer walls 514, a minimum pressure isapplied to the layers disposed in this region. In addition, the proximalrelationship between anvil member 308 and staple cartridge 510′ definesa plurality of gaps therebetween. A first gap is defined between tissuecontacting surfaces 320 and 520 (i.e. along the centerline of staplecartridge 510′), while a second gap is defined between tissue contactingsurfaces 320 and 520 along outer walls 514. As seen in FIG. 10, thefirst gap is not equal to the second gap. Further still, a number ofother gaps may be defined between tissue contacting surfaces 320 and 520at other points of reference existing between the centerline and outerwalls 514 in staple cartridge 510′. Since tissue contacting surface 520slopes toward outer walls 514 to define a substantially uniform angle,the pressure applied to the layers of tissue disposed between tissuecontacting surfaces 320 and 520 uniformly decreases from inner wall 516to outer wall 514.

By angling tissue contacting surface 520 downwards from the centerlineof staple cartridge 510′, reduced compressive forces are applied to thelayers of tissue disposed between tissue contacting surfaces 320 and 520thereby minimizing trauma to the layers of tissue disposed therebetween.Therefore, layers of tissue disposed between tissue contacting surfaces320 and 520 will have a minimum thickness nearest knife channel 530(i.e. nearest the centerline of staple cartridge 510′) and a maximumthickness nearest outer walls 514. In addition, anvil member 308 andstaple cartridge 510′ are dimensioned and arranged such that compressiveforces applied to the layers of tissue are minimal thereby furtherreducing trauma to the layers of tissue. This configuration defines agap between tissue contacting surfaces 320 and 520 that is a maximumalong knife channel 530 (i.e. the centerline of staple cartridge 510 or510′) and a minimum along outer walls of staple cartridge 510 (FIG. 9A)or 510′ (FIG. 10).

Further still, this configuration is applicable to similar staplecartridges and anvil members as will be discussed in detail hereinafterwith respect to FIGS. 11-15. When anvil member 308′ is repositioned intoproximity with staple cartridge 510′ (i.e. in a pre-fire position) toretain layers of body tissue therebetween, the layers of tissue arecompressed. The maximum compression occurs along the centerline (i.e.first or minimum gap) and urges fluid stored in the layers of tissuetowards the outer edges of the tissue (i.e. away from the centerline ofstaple cartridge 510′). By reducing the amount of fluid retained in thelayers of tissue proximal to the centerline, the overall thickness ofthe tissue layers decreases. The decrease in overall tissue thickness issuch that a staple having a shorter leg length (i.e. surgical fastener125 c) is capable of fastening both layers of tissue while minimizingtrauma to the fastened layers of tissue. The gap increases towards theouter walls of staple cartridge 510′ (i.e. the amount of compressiondecreases) and surgical fasteners having a longer leg length (i.e.surgical fasteners 125 a and 125 b) are capable of fastening both layersof tissue.

Leg lengths of surgical fasteners 125 c, 125 b, and 125 a increase in adirection moving from inner walls 516 towards outer walls 514. Byproviding surgical fasteners having increasing leg lengths along a planethat is orthogonal to inner walls 516, the completed (i.e. formed)surgical fasteners join increasing thicknesses of tissue without undulytraumatizing the joined layers of tissue.

In a further embodiment, as illustrated in FIG. 11, operative tool 506″includes staple cartridge 510′ and anvil member 308′. Staple cartridge510′ was previously discussed in detail hereinabove with reference toFIG. 10. Tissue contacting surface 520 may define a more uniform angle(FIG. 11) than in the embodiments of FIGS. 9A and 10 wherein the angleor pitch of tissue contacting surface is substantially constant betweeninner walls 516 and outer walls 514. Anvil member 308′ includes tissuecontacting surface 320′ having tapered surfaces 322′ and 324′. Surfaces322′ and 324′ are connected to outer walls of anvil member 308′ whileextending inwards (i.e. towards the centerline of staple cartridge 510′)and downwards (i.e. towards tissue contacting surface 520) therebydefining an angle. It is envisioned that the angle defined by taperedsurfaces 322′ and 324′ will be substantially similar to the angledefined by tissue contacting surface 520, but in an opposed directionforming a generally V-shaped configuration. Thus, compressive forcesapplied to the layers of tissue will be further reduced thereby furtherreducing the trauma to layers of tissue disposed between tissuecontacting surfaces 520 and 320′. As in the embodiment of FIG. 10, themaximum pressure applied to the layers of tissue will exist in theregion near knife channel 530 while pressures applied to the layers oftissue will decrease uniformly towards outer walls 514. Formation andlocation of surgical fasteners 125 a-c is substantially similar to thatof the embodiment of FIG. 10 along with the attendant advantages.

Referring now to FIG. 12, a further embodiment of the present disclosureis shown as part of operative tool 606. Operative tool 606 includes astaple cartridge 610 and anvil member 308. In this embodiment, tissuecontacting surface 620 includes surfaces 622 and 624. Surface 622 isbisected along its longitudinal axis by knife channel 630 andsubstantially parallel to a bottom surface 612 or parallel to a planedefined by the backspans of surgical fasteners 125 a, 125 b, or 125 c.In addition, surface 622 has a width dimension sufficient to accommodateat least one row of retention slots 623 on each side of knife channel630. Surface 624 connects outer edges of surface 622 to outer walls 614defining an angle on either side of knife channel 630 with respect to aplane that is substantially orthogonal to inner walls 616 (i.e.substantially parallel to surface 622) and has a width dimensionsufficient to accommodate at least one row of retention slots on eachside of knife channel 630. Staple cartridge 610 includes a plurality ofsurgical fasteners 125 a-c and fastener ejection members 540 that werepreviously discussed in detail with respect to FIGS. 9A and 10. Inparticular, staple cartridge 610 includes the arrangement of surgicalfasteners 125 a-c and fastener ejection members 540 as described withrespect to staple cartridge 510′ (FIGS. 10 and 11).

Similar to operative tool 506, tissue contacting surface 320 isrepositioned proximate to tissue contacting surface 620 of staplecartridge 610. In this arrangement, the amount of pressure applied tothe layers of tissue disposed therebetween varies along a plane that istransverse to the longitudinal axis of staple cartridge 610.Specifically, the distance between tissue contacting surface 320 andsurface 622 is a minimum, a maximum pressure is applied to the layers oftissue disposed in this region. Conversely, the distance between tissuecontacting surface 320 and surfaces 624 is at a maximum in the regionnear outer walls 614, a minimum pressure is applied to the layersdisposed in this region. Since surface 624 slopes toward outer walls 614to define a substantially uniform angle, the pressure applied to thelayers of tissue disposed between tissue contacting surface 320 andsurfaces 624 uniformly decreases from an outer edge of surface 622towards outer wall 614.

By angling surface 624 downwards from the edge of surface 622, reducedcompressive forces are applied to the layers of tissue disposed betweentissue contacting surface 320 and surfaces 624 thereby minimizing traumato the layers of tissue disposed therebetween. Layers of tissue disposedbetween tissue contacting surfaces 320 and 620 will have a minimumthickness nearest knife channel 630 and a maximum thickness nearestouter walls 614. In addition, anvil member 308 and staple cartridge 610are dimensioned and arranged such that compressive forces applied to thelayers of tissue are minimal thereby further reducing trauma to thelayers of tissue.

Leg lengths of surgical fasteners 125 c, 125 b, and 125 a increase in adirection moving from inner walls 616 towards outer walls 614. Byproviding surgical fasteners having increasing leg lengths along a planethat is orthogonal to inner walls 616, the completed (i.e. formed)surgical fasteners join increasing thicknesses of tissue without undulytraumatizing the joined layers of tissue.

In a further embodiment, operative tool 606′ is illustrated in FIG. 13.Operative tool 606′ includes staple cartridge 610, that was described indetail hereinabove with respect to FIG. 12, and anvil member 308″. Anvilmember 308″ includes a tissue contacting surface 320″ formed fromsurfaces 332″ and 336″. Surface 336″ is substantially parallel tosurface 622 and has a width dimension that is substantially similar tothe width dimension of surface 622. Surfaces 332″ are tapered andconnected to outer walls of anvil member 308″ and extend inwards (i.e.towards the centerline of staple cartridge 610) and downwards (i.e.towards tissue contacting surface 620) thereby defining an angle. It isenvisioned that the angle defined by tapered surfaces 332″ will besubstantially similar to the angle defined by surfaces 624, but in anopposed direction. Thus, compressive forces applied to the layers oftissue will be further reduced thereby further reducing the trauma tolayers of tissue disposed between surfaces 624 and 332″. As in theembodiment of FIG. 10, the maximum pressure applied to the layers oftissue will exist in the region along surface 622 while pressuresapplied to the layers of tissue will decrease uniformly along surfaces624 towards outer walls 614. Formation and location of surgicalfasteners 125 a-c is substantially similar to that of the embodiment ofFIG. 12 along with the attendant advantages.

In yet another embodiment, operative tool 706 is illustrated in FIG. 14.Staple cartridge 710 is similar to staple cartridge 610. The differencesbetween staple cartridges 610 and 710 will be discussed hereinafter. Asin staple cartridge 610 (FIG. 12), staple cartridge 710 includes tissuecontacting surface 720 formed from surfaces 722 and 724. Surface 722differs from surface 622 in that it has a width dimension sufficient toaccommodate at least two rows of surgical fasteners. As in staplecartridge 610, surfaces 724 are attached to outer edges of surface 722and outer walls 714 to define angles. The interaction between staplecartridge 710 and anvil member 308 for capturing tissue and formingsurgical fasteners is substantially similar to the interaction betweenstaple cartridge 610 and anvil member 308 and, for the sake of brevity,will not be repeated herein.

In FIG. 15, an alternate embodiment of operative tool 706′ isillustrated. Operative tool 706′ includes staple cartridge 710, asdiscussed in detail hereinabove, and anvil member 308″. Anvil member308″ includes a tissue contacting surface 320″ formed from surfaces 332″and 336″. Surface 336″ is substantially parallel to surface 722 and hasa width dimension that is substantially similar to a width dimension ofsurface 722. Surfaces 332″ are tapered and connected to outer walls ofanvil member 308″ and extend inwards (i.e. towards centerline of staplecartridge 710) and downwards (i.e. towards tissue contacting surface720) thereby defining an angle. It is envisioned that the angle definedby tapered surfaces 332″ will be substantially similar to the angledefined by surfaces 724, but in an opposed direction. Thus, compressiveforces applied to the layers of tissue will be further reduced, therebyfurther reducing the trauma to the layers of tissue disposed betweensurfaces 724 and 332″. As in the embodiment of FIG. 14, the maximumpressure applied to the layers of tissue will exist in the region alongsurface 722 while pressures applied to the layers of tissue willdecrease uniformly along surfaces 724 towards outer walls 714. Formationand location of surgical fasteners 125 a-c is substantially similar tothat of the embodiment of FIG. 14 along with the attendant advantages.

Turning now to FIG. 16B, a cross-section of the resulting tissueinterface, following the firing of staple cartridge 510′, is shown. Asseen in FIG. 16B, the tissue interface has a substantially taperedprofile. In particular, some or all of surgical fasteners 125 a-125 cserve to hold tissues “A” and “B” to one another while surgicalfasteners 125 c also provide the hemostasis. This resultingcross-section is also applicable to the firing of staple cartridges 610and 710. When staple cartridge 510 is fired, some or all of surgicalfasteners 125 a-5 c serve to hold tissues “A” and “B” to one anotherwhile surgical fasteners 125 a also provide the hemostasis. When layersof tissue “A” and “B” are fastened using a conventional surgicalstapling device and conventional staples “S”, there exists a sharptransition from the un-fastened layers of tissue to the fastened layersof tissue that is illustrated in FIG. 16A. This may result in a greaterload being placed on the layers of tissue and may produce an undesirableeffect on the layers of tissue. In comparison, as shown in FIG. 16B, thetissue interface has a gradual transition from the un-fastened layers oftissue to the fastened layers of tissue and also within the fastenedlayers of tissue. This arrangement provides gradual tissue loading orcompression due to the varying sizes of the formed surgical fasteners125 a-c, thereby minimizing tissue trauma while maintaining a relativelyhigh degree of hemostasis and anastomotic strength.

In a further embodiment of the present disclosure, as shown in FIGS. 8and 10, operative tool 506′ includes a wound closure assembly 50. Woundclosure assembly 50 includes at least one storage device or reservoir 52and at least one supply line 54. Supply line 54 fluidly couplesreservoir 52 to staple cartridge 510′ for delivering an amount of awound closure material “W”. In particular, supply line 54 delivers woundclosure material “W” into knife channel 530 such that when surgicalfasteners 125 a-c are formed, wound closure material “W” migrates alongthe layers of tissue adjacent to tissue contacting surface 520 (i.e. thetarget site). By providing wound closure material “W” in combinationwith surgical fasteners 125 a-c, the bond formed between the layers oftissue has improved strength.

Compression of reservoir 52 causes wound closure material “W” containedtherein to be urged through supply line 54 and dispensed via knifechannel 530. Preferably, wound closure material “W” is dispensed duringthe staple firing procedure so that wound closure material “W” isdispensed along the length of the staple line and/or a knife cut line.Although wound closure assembly is discussed and illustrated withrespect to FIG. 10, it is contemplated that wound closure assembly 50 isadaptable for use with other disclosed embodiments of staple cartridge510′ (i.e. 510, 610, or 710). It is further contemplated that anadditional reservoir may be included for wound closure materials formedby combining two substances or that reservoir 52 may include a pluralityof internal chambers (shown in phantom) for storing quantities ofsubstances to be combined to form wound closure material “W”.

It is envisioned that wound closure material “W” can include one or acombination of adhesives, hemostats, sealants. Surgical biocompatiblewound closure materials which can be employed in or applied the surgicalinstruments, especially surgical staplers, include adhesives whosefunction is to attach or hold organs, tissues or structures, sealants toprevent fluid leakage, and hemostats to halt or prevent bleeding.Examples of adhesives which can be employed include protein derived,aldehyde-based adhesive materials, for example, the commerciallyavailable albumin/glutaraldehyde materials sold under the tradedesignation BIOGLUE™ by Cryolife, Inc., and cyanoacrylate-basedmaterials sold under the trade designations INDERIVIIL™ and DERMA BOND™by Tyco Healthcare Group, LP and Ethicon Endosurgery, Inc.,respectively. Examples of sealants, which can be employed, includefibrin sealants and collagen-based and synthetic polymer-based tissuesealants. Examples of commercially available sealants are syntheticpolyethylene glycol-based, hydrogel materials sold under the tradedesignation COSEAL™ by Cohesion Technologies and Baxter International,Inc. Examples of hemostat materials, which can be employed, includefibrin-based, collagen-based, oxidized regenerated cellulose-based andgelatin-based topical hemostats. Examples of commercially availablehemostat materials are fibrinogen-thrombin combination materials undersold the trade designations COSTASIS™ by Tyco Healthcare Group, LP, andTISSEEL™ sold by Baxter International, Inc. Hemostats herein includeastringents, e.g., aluminum sulfate, and coagulants.

It is to be understood that the dispensing of wound closure material “W”can be as a fluid spray of any suitable volume, including a mist,applied temporarily, continuously, or continually. Particulate material,e.g. a fine powder is contemplated to be a fluid within the scope ofthis disclosure.

It is provided that a number of different wound closure materials “W”can be dispensed by wound closure assembly 50 or a combination of thenumber of different wound closure materials “W”. The wound closurematerial dispensed by wound closure assembly 50 can, for example, be anastringent, such as a sulfate of aluminum, which causes small bloodvessels to close and helps the blood to coagulate. It is provided thatwound closure material “W” can be an astringent provided in the materialcommercially available under the trade designation NO NIX® StypticPencils from Requa, Inc.

Referring now to FIGS. 17A-F, further embodiments of the presentlydisclosed operative tool are illustrated. As shown in FIG. 17A,operative tool 806 a includes anvil member 308 and staple cartridge 810a. Anvil member 308 was previously described hereinabove with referenceto FIG. 9A and, for the sake of brevity, will not be discussed again. Inaddition, staple cartridge 810 a is similar to staple cartridge 710(FIG. 14) with the differences being discussed in detail hereinbelow.Similar to staple cartridge 710, staple cartridge 810 a includes atissue contacting surface 820, outer and inner walls 814, 816, a knifechannel 830, and a bottom surface 812. Located within staple cartridge810 a is a plurality of surgical fasteners 125 a, 125 b, and 125 c thatwere previously discussed with respect to staple cartridge 710. Inaddition, staple cartridge 810 a includes a plurality of fastenerejection members 540 that were previously described with respect to FIG.9.

In this embodiment, surfaces 822 and 824 define tissue contactingsurface 820. As with previous embodiments of the presently disclosedstaple cartridge, tissue contacting surface 820 includes a plurality ofretention slots 823. Surface 822 is a planar surface that issubstantially parallel to bottom surface 812, while surface 824 is agenerally arcuate surface. Each surface 822, 824 includes at least onerow of retention slots 823. Additionally, inner wall 816 has a firstheight and outer wall 814 has a second height, wherein the first heightis greater than the second height. One edge of surface 824 is attachedto outer wall 814 while the opposing edge is attached to an edge ofsurface 822, thereby defining a generally concave surface with respectto surface 822.

Similar to previous embodiments of the presently disclosed operativetool, tissue contacting surface 320 of anvil member 308 is repositionedproximate to tissue contacting surface 820 of staple cartridge 810 a. Inthis arrangement, the amount of pressure applied to the layers of tissuedisposed therebetween varies along a plane that is transverse to thelongitudinal axis of staple cartridge 810 a. Specifically, the distancebetween tissue contacting surface 320 and surface 822 is a minimum, suchthat a maximum pressure is applied to the layers of tissue disposed inthis region. Conversely, the distance between tissue contacting surface320 and surfaces 824 is at a maximum in the region near outer walls 814,such that a minimum pressure is applied to the layers disposed in thisregion. Since surface 824 curves downward as it approaches outer walls814, the pressure applied to the layers of tissue disposed betweentissue contacting surface 320 and surfaces 824 decreases from an outeredge of surface 822 towards outer wall 814. The amount of pressuredecrease is a function of curvature of surface 824.

By curving surface 824 downwards from the edge of surface 822, reducedcompressive forces are applied to the layers of tissue disposed betweentissue contacting surface 320 and surfaces 824 thereby minimizing traumato the layers of tissue disposed therebetween. Layers of tissue disposedbetween tissue contacting surfaces 320 and 820 will have a minimumthickness nearest knife channel 830 and a maximum thickness nearestouter walls 814. In addition, anvil member 308 and staple cartridge 810a are dimensioned and arranged such that compressive forces applied tothe layers of tissue are minimal thereby further reducing trauma to thelayers of tissue.

Leg lengths of surgical fasteners 125 c, 125 b, and 125 a increase in adirection moving from inner walls 816 towards outer walls 814. Byproviding surgical fasteners having increasing leg lengths along a planethat is orthogonal to inner walls 816, the completed (i.e. formed)surgical fasteners join increasing thicknesses of tissue without undulytraumatizing the joined layers of tissue. A more detailed description ofsurgical fasteners 125 a-c and fastener ejection members 540 isdiscussed hereinabove with reference to FIG. 9.

In the embodiment illustrated in FIG. 17B, operative tool 806 b includesstaple cartridge 810 b that is substantially similar to staple cartridge810 a with the differences between them being discussed below. In staplecartridge 810 b, outer walls 814′ and inner walls 816′ have a lowerheight than outer walls 814 and inner walls 816 of staple cartridge 810a. In this configuration, tissue contacting surface 820 is closer tobottom surface 812 such that tips of surgical fasteners 125 a, 125 b,and 125 c extend into retention slots 823 and are substantially flushwith tissue contacting surface 820.

Referring now to FIGS. 17C and 17D, operative tools 806 c and 806 d areillustrated. Operative tools 806 c and 806 d include staple cartridges810 a and 810 b (as discussed hereinabove) respectively. In theseembodiments, anvil member 308 a replaces anvil member 308. In thisembodiment, anvil member 308 a includes a tissue contacting surface 320a formed from surfaces 332 a and 336 a. Surface 336 a is substantiallyparallel to surface 822 and has a width dimension that is substantiallysimilar to the width dimension of surface 822. Surfaces 332 a aregenerally arcuate such that a thickness of anvil member 308 a is at aminimum in the region near its outer edge and a maximum along surface336 a. It is envisioned that the curve defined by surfaces 332 a will besubstantially similar to the curve defined by surfaces 824, but in anopposed direction (i.e. defining a convex relationship with respect tosurface 822). Thus, compressive forces applied to the layers of tissuewill be further reduced, thereby further reducing trauma to the layersof tissue positioned between surfaces 824 and 332 a.

As in the embodiment of FIGS. 17A and 17B, the maximum pressure appliedto the layers of tissue will exist in the region along surface 822 whilepressures applied to the layers of tissue will decrease along surfaces824 towards outer walls 814, 814′. The decrease in pressure along thegradient defined by surfaces 824 and 332 a is proportional to thecurvature of each surface. Formation and location of surgical fasteners125 a-c is substantially similar to that of the embodiment of FIGS. 17Aand 17B along with the attendant advantages.

In a further embodiment, operative tool 906 is illustrated in FIG. 18A.Operative tool 906 includes anvil member 308 and staple cartridge 910.Staple cartridge 910 is substantially similar to staple cartridge 810wherein the same or similar components are renumbered accordingly andthe differences discussed in detail hereinafter. Tissue contactingsurface 920 includes surfaces 922 and 924 wherein each surface includesa plurality of retention slots 923. Similar to the embodiment shown inFIGS. 17A-D, surface 922 is a generally planar surface that issubstantially parallel to a bottom surface 912 and defines a right angleat its junction with inner wall 916. Surface 924 is also a generallyplanar surface that substantially parallel with bottom surface 912 andsurface 922, wherein surfaces 922 and 924 are vertically spaced apartsuch that they are not coplanar with one another. Additionally, innerwall 916 has a first height and outer wall 914 has a second height,wherein the first height is greater than the second height.

As in the previous embodiments of the presently disclosed operativetool, tissue contacting surface 320 of anvil member 308 is repositionedproximate to tissue contacting surface 920 of staple cartridge 910. Inthis arrangement, the amount of pressure applied to the layers of tissuedisposed therebetween varies along a plane that is transverse to thelongitudinal axis of staple cartridge 910. Specifically, the distancebetween tissue contacting surface 320 and surface 922 is a minimum, suchthat a maximum pressure is applied to the layers of tissue disposed inthis region. Conversely, the distance between tissue contacting surface320 and surfaces 824 is at a maximum, such that a minimum pressure isapplied to the layers disposed in this region. Since surface 924 isgenerally planar, the pressure applied to the layers of tissue disposedbetween tissue contacting surface 320 and surfaces 924 is substantiallyuniform and less than the pressure applied to the layers of tissuepositioned between tissue contacting surface 320 and surface 922.

Leg lengths of surgical fasteners 125 c, 125 b, and 125 a increase in adirection moving from inner walls 916 towards outer walls 914. Byproviding surgical fasteners having increasing leg lengths along a planethat is orthogonal to inner walls 916, the completed (i.e. formed)surgical fasteners join increasing thicknesses of tissue without undulytraumatizing the joined layers of tissue. A more detailed description ofsurgical fasteners 125 a-c and fastener ejection members 540 isdiscussed hereinabove with reference to FIG. 9.

Referring now to FIG. 17E, a further embodiment of operative tool 806 isillustrated and referenced as operative tool 806 e. Operative tool 806 eincludes substantially the same or similar components as operative tool806 a (FIG. 17A) with the differences being discussed hereinafter. Inparticular, operative tool 806 e includes anvil member 308 and staplecartridge 810 b. Staple cartridge differs from staple cartridge 810 a inthat tissue contacting surface 824 a is an arcuate structure extendingfrom the centerline to outer walls 514 of staple cartridge 810 b. Thearrangement between tissue contacting surface 824 a and tissuecontacting surface 320 provides the same advantages and benefits as doesthe arrangements provided in the embodiments illustrated in FIGS. 17A-D.

Alternatively, staple cartridge 810 b may be used with anvil member 308d to form operative tool 806 f that is illustrated in FIG. 17F. Anvilmember 308 d includes tissue contacting surface 320 d that issubstantially complementary to tissue contacting surface 824 a. In thisconfiguration, a substantially uniform gap is maintained between thesurfaces from the centerline of operative tool 806 f to its outer walls814.

A further embodiment of the presently disclosed operative tool isillustrated in FIG. 18B wherein anvil member 308 is replaced by anvilmember 308 b. Operative tool 906 a includes staple cartridge 910 andanvil member 308 b. In particular, anvil member 308 b includes a tissuecontacting surface 320 b that is defined by surfaces 332 b and 336 b.Similar to the embodiment shown in FIG. 17D, tissue contacting surface320 b of anvil member 308 b is complementary to tissue contactingsurface 920 of staple cartridge 910 such that a greater gap is definedbetween surfaces 924 and 332 b than between surfaces 924 and tissuecontacting surface 320 (FIG. 18A). In this configuration, a reducedamount of pressure is applied to the layers of tissue capturedtherebetween.

Referring now to FIGS. 19A and 19B, operative tools 1006 a and 1006 bare illustrated. Operative tool 1006 a includes anvil member 308 and astaple cartridge 1010. Staple cartridge 1010 is substantially similar tostaple cartridge 510 wherein the same or similar components arerenumbered accordingly and the differences discussed in detailhereinafter. Surface 1020 is substantially planar and substantiallyparallel to bottom surface 1012. In this embodiment, a filler layer 1070is positioned on surface 1020. Filler layer 1070 is formed from amaterial that has sufficient resiliency to support layers of tissuewhile permitting surgical fasteners 125 a-c to pass through during theformation of completed surgical fasteners. Filler layer 1070 may be abuttress material that is an organic or synthetic tissue used toreinforce tissue at a staple line. An example of a suitable materialincludes SEAMGUARD® from W.L. Gore & Associates, Inc.

Filler layer 1070 is a generally triangular structure that tapers from amaximum height near knife channel 1030 towards a minimum height nearouter walls 1014. Thus, the gap defined between tissue contactingsurface 320 and filler layer 1070 is at a minimum near knife channel1030 and at a maximum near outer walls 1014. As such, the amount ofpressure applied to layers of tissue captured between tissue contactingsurface 320 and filler layer 1070 is at a minimum near knife channel1030 and at a maximum near outer walls 1014, thereby providing theattendant advantages as in previous embodiments with respect to formingthe surgical fasteners and minimizing trauma to the layers of tissue. Inaddition, filler layer 1070 may be formed from a resilient orsemi-resilient material, thereby further minimizing trauma to the layersof tissue that are captured between tissue contacting surface 320 andsurface 1020.

Alternatively, a second filler layer 1070, shown in phantom, may bepositioned on tissue contacting surface 320. Staple cartridge 1010 mayinclude filler layer 1070 disposed on tissue contacting surface 1020, ontissue contacting surface 320, or on both tissue contacting surfaces320, 1020 according to the surgical procedure to be performed.

In FIG. 19B, operative tool 1006 b includes previously described staplecartridge 1010 in cooperation with anvil member 308′. Anvil member 308′includes tissue contacting surface 320′ having tapered surfaces 322′ and324′. Surfaces 322′ and 324′ are connected to outer walls of anvilmember 308′ while extending inwards (i.e. towards the centerline ofstaple cartridge 1010) and downwards (i.e. towards tissue contactingsurface 1020) thereby defining an angle. It is envisioned that the angledefined by tapered surfaces 322′ and 324′ will be substantially similarto the angle defined by filler layer 1070, but in an opposed directionforming a generally V-shaped configuration. Thus, compressive forcesapplied to the layers of tissue will be further reduced thereby furtherreducing the trauma to layers of tissue disposed between tissuecontacting surface 320′ and filler layer 1070. The maximum pressureapplied to the layers of tissue will exist in the region near knifechannel 1030 while pressures applied to the layers of tissue willdecrease uniformly towards outer walls 1014. Formation and location ofsurgical fasteners 125 a-c is substantially similar to that of theembodiment of FIG. 19A along with the attendant advantages.

Turning now to FIG. 20A, an alternate embodiment of staple cartridge412′ (FIG. 7A) is illustrated and described hereinafter. Staplecartridge 412″ is similar to staple cartridge 412′ wherein the same orsimilar components are renumbered accordingly and the differencesdiscussed in detail hereinafter. Staple cartridge 412″ includes aplurality of tissue contacting surfaces 421 a-c, wherein each tissuecontacting surface is a generally planar structure. Of the threesurfaces, tissue contacting surface 421 b has the greatest height and isvertically spaced apart from tissue contacting surfaces 421 a and 421 c.Tissue contacting surfaces 421 a-c are substantially parallel with oneanother, wherein tissue contacting surface 421 b does not lie in thesame plane as either of tissue contacting surfaces 421 a or 421 c.

Anvil member 408 includes pockets 450 and tissue contacting surface 430.Pockets 450 substantially align with retention slots 123 for formingcompleted surgical fasteners. In this configuration, a minimum gap isdefined between tissue contacting surface 430 and tissue contactingsurface 421 b while a maximum gap is defined between tissue contactingsurface 430 and tissue contacting surfaces 421 a and 421 c. Surgicalfasteners 425 a-c are associated with tissue contacting surfaces 421 a-crespectively. Surgical fasteners 425 a-c are substantially similar tosurgical fasteners 125 a-c and the differences between them arediscussed in detail hereinafter. In one embodiment, surgical fasteners425 a and 425 c are substantially identical and have a greater leglength than surgical fastener 425 b. By providing this arrangement oftissue contacting surfaces and surgical fasteners, reduced compressiveforces are applied to the layers of tissue disposed between tissuecontacting surface 430 and tissue contacting surfaces 421 a, 421 c aswas discussed previously with respect to other embodiments of thepresently disclosed staple cartridge.

In the alternative, staple cartridge 412″ may be used in cooperationwith anvil member 408 a as illustrated in FIG. 20B. Anvil member 408 aincludes pockets 450 and tissue contacting surface 430′. Further still,tissue contacting surface 430′ includes surfaces 432 and 434. Each ofsurfaces 432, 434 are generally planar surfaces that are substantiallyparallel to tissue contacting surfaces 421 a-c of staple cartridge 412″.Surfaces 432 are vertically spaced apart from surface 434 such that thegap defined between surface 434 and tissue contacting surface 421 b is aminimum while the gap defined between surfaces 432 and tissue contactingsurfaces 421 a, 421 c is a maximum. Thus, reduced compressive forces areapplied to the layers of tissue disposed between tissue contactingsurfaces 421 a, 421 c and surfaces 432 of anvil member 408 a.

Alternatively, staple cartridge 412″ may be used in cooperation withanvil member 408 b as illustrated in FIG. 20C. Anvil member 408 bincludes surfaces 432 a and 434 a. In contrast to surfaces 432 and 434of anvil member 408 a (FIG. 20B), surfaces 432 a and 434 a are generallyarcuate. In this configuration, any potential trauma to tissuepositioned between anvil member 408 b and staple cartridge 412″ isreduced while maintaining the advantages and benefits of an increasedgap between tissue contacting surfaces of anvil member 408 b and staplecartridge 412″.

A further embodiment of the presently disclosed operative tool isillustrated in FIG. 21A and generally designated as 1106. Operative tool1106 includes staple cartridge 1110 and anvil member 308. Anvil member308 was previously described in detail with reference to FIG. 9. Staplecartridge 1110 includes the same or substantially similar components tostaple cartridge 510 (FIG. 9), wherein the same or similar componentsare renumbered accordingly and the differences discussed in detailhereinafter.

In particular, staple cartridge 1110 includes surgical fasteners 125 a-cand corresponding pushers 1140. In addition, staple cartridge 1110includes outer walls 1114, inner walls 1116, and vertical members 1118.Inner walls 1116 may be spaced apart for defining a knife channel 1130therebetween. In addition, vertical members 1118 are generally planarstructures that abut inner walls 1116 and generally have a height atleast equal to that of inner walls 1116. A top plate 1154 is a generallyplanar structure that connects inner wall 1116 and outer wall 1114. Inone embodiment, top plate 1154 is substantially parallel to bottomsurface 1112. In addition, top plate 1154 includes a plurality ofretention slots 1123. Vertically spaced above top plate 1154 is crossmember 1150.

Cross member 1150 includes a plurality of openings 1125 that are alignedwith retention slots 1123 of top plate 1154. In addition, cross member1150 defines a tissue contacting surface 1120 that is substantiallyparallel to bottom surface 1112 in a first position. Specifically, aninner edge of cross member 1150 is flexibly attached to an edge ofvertical member 1118 while an outer edge 1156 is spaced apart from a topedge 1114 a of outer wall 1114 defining a gap 1152 therebetween. Crossmember 1150 has sufficient rigidity such that when layers of tissue arepositioned between tissue contacting surfaces 320 and 1120, cross member1150 maintains its substantially parallel relationship to bottom surface1112. Gap 1152 may include an elastomeric compression member thatcontrols the amount of deflection by tissue contacting surface 1120.

As anvil member 308 and staple cartridge 1110 are brought into a closercooperative arrangement (i.e. during approximation and/or formation ofthe surgical fasteners), compressive forces generated by the relativemovement between anvil member 308 and staple cartridge 1110 urge outeredge 1156 towards top edge 1114 a, thereby reducing gap 1152. Inaddition, cross member 1154 (shown in phantom) flexes towards bottomwall 1112, thereby providing an increased distance between tissuecontacting surfaces 320 and 1120 at outer wall 1114 while maintaining afixed (i.e. unflexed) distance between tissue contacting surfaces 320and 1120 at vertical member 1118. As cross member 1154 flexes, thedistance between tissue contacting surfaces 320 and 1120 increases alongan axis that is transverse to a longitudinal axis of staple cartridge1110. The distance between tissue contacting surfaces 320 and 1120 atany selected position along the transverse axis is related to the amountof flexion provided by cross member 1154. Cross member 1150 ispositionable throughout a plurality of positions including at least afirst position that is substantially parallel to bottom surface 1112 anda second position wherein outer edge 1156 is in contact with top edge1114 a.

When tissue contacting surface 320 of anvil member 308 is repositionedproximate to tissue contacting surface 1120 of staple cartridge 1110,the amount of pressure applied to the layers of tissue disposedtherebetween varies along a plane that is transverse to the longitudinalaxis of staple cartridge 1110. Since tissue contacting surface 1120slopes toward outer walls 1114, the pressure applied to the layers oftissue disposed between tissue contacting surfaces 320 and 1120decreases from inner wall 1116 to outer wall 1114. Further still, whencross member 1150 flexes towards top plate 1154, it defines a curvatesurface similar to tissue contacting surface 520 (FIG. 9). Openings 1125have a greater width dimension such that when cross member 1150 is urgedtowards top plate 1154, the alignment of openings 1125 and retentionslots 1123 is such that an unobstructed path is defined for surgicalfasteners 125 a-c, thereby allowing surgical fasteners 125 a-c to engagelayers of tissue and contact anvil member 308.

By flexing tissue contacting surface 1120 downwards from the centerlineof staple cartridge 1110, reduced compressive forces are applied to thelayers of tissue disposed between tissue contacting surfaces 320 and1120 thereby minimizing trauma to the layers of tissue disposedtherebetween. Therefore, layers of tissue disposed between tissuecontacting surfaces 320 and 1120 will have a minimum thickness nearestknife channel 1130 (i.e. nearest the centerline of staple cartridge1110) and gradually increasing to a maximum thickness nearest outerwalls 1114.

Leg lengths of surgical fasteners 125 c, 125 b, and 125 a increase in adirection moving from inner walls 1116 towards outer walls 1114. Byproviding surgical fasteners having increasing leg lengths along a planethat is orthogonal to inner walls 1116, the completed (i.e. formed)surgical fasteners join increasing thicknesses of tissue without undulytraumatizing the joined layers of tissue.

Referring now to FIG. 21B, an alternate embodiment of the presentlydisclosed operative tool is illustrated and referenced as 1106 a.Operative tool 1106 a includes staple cartridge 1110, as discussedabove, in cooperation with anvil member 308′ that was discussed indetail with reference to FIG. 11. Anvil member 308′ includes tissuecontacting surface 320′ having tapered surfaces 322′ and 324′. It isenvisioned that the angle defined by tapered surfaces 322′ and 324′ willbe substantially similar to the angle defined by tissue contactingsurface 1120, but in an opposed direction forming a generally V-shapedconfiguration. Thus, compressive forces applied to the layers of tissuewill be further reduced thereby further reducing the trauma to layers oftissue disposed between tissue contacting surfaces 1120 and 320′. As inthe previous embodiments, the maximum pressure applied to the layers oftissue will exist in the region near knife channel 1130 while pressuresapplied to the layers of tissue will decrease uniformly towards outerwalls 1114. Formation and location of surgical fasteners 125 a-c issubstantially similar to that of the embodiment of FIG. 21A along withthe attendant advantages.

Further embodiments are illustrated in FIGS. 22A-C and discussedhereinbelow. Referring initially to FIG. 22A, operative tool 1206 a isillustrated and includes anvil member 308 d and staple cartridge 1210.In particular, staple cartridge 1210 includes surgical fasteners 125 a-cand fastener ejection members 540 that were previously discussed indetail with respect to FIG. 9A. Similar to previous embodiments, staplecartridge 1210 includes a bottom surface 1212, outer walls 1214, innerwalls 1216, and a knife channel 1230. In addition, staple cartridge 1210includes a tissue contacting surface 1220 formed from surfaces 1222 and1224. Each of surfaces 1222 and 1224 has a width dimension that issufficient to accommodate at least one row of surgical fasteners. Asshown in FIG. 22A, surface 1222 is substantially parallel to bottomsurface 1212, while surface 1224 is a generally arcuate structure.Further still, the topmost portions of surfaces 1224 have substantiallythe same height dimension as measured from bottom surface 1212. Acomplementary anvil member 308 d is provided in operative tool 1206 awherein anvil member 308 d includes a substantially planar surface 322 dthat corresponds to surfaces 1222 and knife channel 1230. Additionally,anvil member 308 d includes surfaces 324 d that are generally arcuate soas to correspond to surfaces 1224 of staple cartridge 1210. By providingthis arrangement between staple cartridge 1210 and anvil member 308 d, asubstantially uniform tissue gap is defined between the surfaces ofanvil member 308 d and staple cartridge 1210.

Alternatively, operative tool 1206 b, as shown in FIG. 22B, includesanvil member 308 e in cooperation with staple cartridge 1210 a. Staplecartridge 1210 a is substantially similar to staple cartridge 1210 (FIG.22A) with the differences therebetween discussed below. Most notably,tissue contacting surface 1220 a includes surfaces 1222 a, 1224 a, and1226 a. Surfaces 1222 a and 1224 a are substantially similar to surfaces1222 and 1224 of FIG. 22A, while surface 1226 is a generally arcuatestructure having a lower height dimension that surface 1224 (i.e. withrespect to bottom surface 1212). Thus, surfaces 1222, 1224, and 1226“step down” from the centerline towards outer walls 1214 of staplecartridge 1210 a. Anvil member 308 e has a tissue contacting surface 320e that substantially complements tissue contacting surface 1220 a. Assuch, tissue contacting surface 320 e includes a substantially planarsurface 322 e that corresponds to surfaces 1222 a and knife channel1230. Additionally, anvil member 308 d includes surfaces 324 e and 326 ethat are generally arcuate so as to correspond to surfaces 1224 a and1226 a of staple cartridge 1210 a. By providing this arrangement betweenstaple cartridge 1210 a and anvil member 308 e, a substantially uniformtissue gap is defined between the surfaces of anvil member 308 e andstaple cartridge 1210 a.

Alternatively, staple cartridge 1210 a may be used in cooperation withanvil member 308 as shown in FIG. 22C. In this configuration, the gapdefined between tissue contacting surfaces 320 and 1220 b increases froma first gap at knife channel 1230 to a second gap at outer walls 1214,wherein the second gap is greater than the first gap.

In a further embodiment of the present disclosure, an operative toolassembly is illustrated in FIGS. 23-30 and generally referenced as 1300.As in the previously disclosed embodiments, operative tool assembly 1300includes a staple cartridge 1310 and an anvil member 1340. Tool assembly1300 includes a body 1302 for receiving staple cartridge 1310.

Anvil member 1340 optionally includes a slot 1342 in tissue contactingsurface 1306. Tissue contacting surface 1306 includes staple formingdepressions. A pair of tabs 1344 is located in a proximal portion ofanvil member 1340 and cooperates with recesses 1304 of body 1302. Assuch, anvil member 1340 is pivotably coupled to body 1302 and isrepositionable between an open position and an approximate position. Inthe open position, anvil member 1340 is spaced apart from staplecartridge 1310 and allows tissue to be positioned therebetween. In theapproximated position, anvil member 1340 cooperates with staplecartridge 1310 and captures tissue therebetween. Slot 1342 is configuredfor allowing the passage of a knife blade (not shown) as the knife bladepasses longitudinally through anvil member 1340 and staple cartridge1310. In certain embodiments, the knife blade is carried on, orintegrally formed with, a drive beam (not shown) that is advanceddistally through anvil member 1340 and staple cartridge 1310 forapproximating anvil cartridge 1340 and staple cartridge 1310 withrespect to one another, and to deploy staples from staple cartridge 1310against anvil member 1340. Operative tool assembly 1300 may be arrangedas described in U.S. Pat. No. 5,865,361, the disclosure of which ishereby incorporated by reference herein in its entirety. In otherembodiments, anvil member 1340 and staple cartridge 1310 areapproximated with respect to one another by the advancement distally ofa clamp tube, such as disclosed in U.S. Pat. No. 5,318,221, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

Staple cartridge 1310 includes a plurality of tissue contactingsurfaces. In one embodiment, staple cartridge 1310 includes tissuecontacting surfaces 1312, 1314, and 1316. Tissue contacting surfaces1312, 1314, and 1316 are substantially planar surfaces that aresubstantially parallel to the other tissue contacting surfaces, but arespaced apart (i.e. the tissue contacting surfaces are in a steppedconfiguration) as seen in FIGS. 24 and 29. Referring also to FIG. 29, awall surface 1315 extends between tissue contacting surfaces 1312 and1314, while a wall surface 1317 extends between tissue contactingsurfaces 1314 and 1316. Wall surfaces 1315, 1317 are generally planarsurfaces that define an angle with respect to an adjacent tissuecontacting surface. As illustrated in FIG. 29, wall surfaces 1315, 1317are arranged such that each of the wall surfaces is in an angularrelationship with the adjacent tissue contacting surfaces 1312, 1314,and 1316. The angle defined between the wall surface and the adjacenttissue contacting surface may be in a range of angles that is greaterthan 0° to about 90°.

Providing tissue contacting surfaces 1312, 1314, and 1316 in a steppedconfiguration (FIG. 29), improves the anastomotic strength and thedegree of hemostasis obtained at the cut line when layers of body tissueare clamped between anvil member 1340 and staple cartridge 1310. Inparticular, this arrangement provides gradual tissue loading orcompression due to the varying gap defined between tissue contactingsurface 1306 of anvil member 1340 and tissue contacting surfaces 1312,1314, 1316 of staple cartridge 1310 when they are in the approximatedposition, thereby minimizing tissue trauma while maintaining arelatively high degree of hemostasis and anastomotic strength. Notably,when anvil member 1340 and staple cartridge 1310 are in the approximatedposition, first, second, and third tissue gaps are defined betweentissue contacting surfaces 1312, 1314, 1316 and a tissue contactingsurface 1306 of anvil member 1340. As such, the first tissue gap 1321 isthe smallest, while the third tissue gap 1323 is the greatest with thesecond tissue gap 1322 in-between the first and third tissue gaps. It isenvisioned that the tissue contacting surface 1306 of anvil member 1340includes a plurality of depressions for forming completed surgicalfasteners.

Staple cartridge 1310 includes a plurality of surgical fastenersdisposed in retention slots 1330 that are open at tissue contactingsurfaces 1312, 1314, 1316. Referring now to FIGS. 25 and 26, thearrangement of the surgical fasteners is illustrated. Staple cartridge1310 includes surgical fasteners or staples 1325 a, 1325 b, and 1325 c.Staples 1325 a, 1325 b, and 1325 c are substantially similar to staples25 a, 25 b, and 25 c that were previously discussed. Staples 1325 a,1325 b, and 1325 c each include a backspan 1337. Briefly, legs 1327 a ofsurgical fasteners 1325 a have a first leg length, legs 1327 b ofsurgical fasteners 1325 b have a second leg length, and legs 1327 c ofsurgical fasteners 1325 c have a third leg length. In one embodiment,legs 1327 c of surgical fasteners 1325 c have a leg length of about 3.0mm, legs 1327 b of surgical fasteners 1325 b have a leg length of about3.5 mm, and legs 1327 a of surgical fasteners 1325 a have a leg lengthof about 4.0 mm. It is contemplated that other embodiments of thepresent disclosure include legs 1327 c in a range of about 2.0 mm toabout 4.0 mm, legs 1327 b in a range of about 2.5 mm to about 4.5 mm,and legs 1327 a in a range of about 3.0 mm to about 5.0 mm. In certainpreferred embodiments, surgical fasteners 1325 a have the longest leglength, surgical fasteners 1325 c have the shortest leg length, andsurgical fasteners 1325 b have a leg length therebetween. It iscontemplated that the staples in the staple cartridge 1310 can rangefrom about 2.0 mm to about 5.0 mm. Surgical fasteners 1325 a arearranged in a longitudinally extending row located in tissue contactingsurface 1312; surgical fasteners 1325 b are arranged in a longitudinallyextending row located in tissue contacting surface 1314; and surgicalfasteners 1325 c are arranged in a longitudinally extending row locatedin tissue contacting surface 1316. In this arrangement, layers of bodytissue that are fastened using staple cartridge 1310 have improvedhemostasis and anastomotic strength. It is envisioned and within thescope of the present disclosure that any number of arrangements arepossible.

Surgical fasteners 1325 a-c cooperate with staple pusher 30 (FIG. 26)and sled 1350 (FIG. 25) such that the longitudinal translation of sled1350 by a drive beam through staple cartridge 1310 urges pushers 30 in avertical direction to eject surgical fasteners 1325 a-c. As shown inFIG. 26, staple pusher 30 includes pusher plates 32, 34, and 36, each ofwhich has a different vertical dimension. Pusher plate 32 has thegreatest vertical dimension and cooperates with surgical fastener 1325c, while pusher plate 36 has the smallest vertical dimension andcooperates with surgical fastener 1325 a. Pusher plate 34 has a verticaldimension greater than pusher plate 36, but less than pusher plate 32and cooperates with surgical fastener 1325 b. By providing surgicalfasteners 1325 a-c and pusher plates 30 with complementary heights, tipsof surgical fasteners 1325 a-c are substantially flush with theirrespective tissue contacting surfaces prior to ejecting surgicalfasteners 1325 a-c from their respective retention slots. It is alsoenvisioned that other arrangements of pusher plates and surgicalfasteners may be used. For example, the pusher plates may have heightsthat are selected to define a gap with the tissue contacting surface1306 for forming a staple having a leg length of a particular size.

As illustrated in FIG. 25, staple cartridge 1310 fits into cartridgebody 1302. In one embodiment, staple cartridge 1310 is replaceable.After the user has fired the staples in staple cartridge 1310, the userremoves staple cartridge 1310 from cartridge body 1302 and installs anew staple cartridge 1310 having a full complement of staples. In analternate embodiment, staple cartridge 1310 is fixedly attached tocartridge body 1302. In such an embodiment, operative tool assembly 1300including anvil member 1340, body 1302, and staple cartridge 1310 mayconstitute a replaceable loading unit so that upon the installation of anew loading unit, a new knife blade is also provided. Staple cartridge1310 may also include a knife channel 1318 to allow passage of a knifeblade and drive beam.

In a certain embodiments, the staples are arranged in the staplecartridge 1310 so that staples 1325 a are disposed in retention slots1330 (FIG. 29) that extend in a linear row, along tissue contactingsurface 1312. Staples 1325 b are disposed in retention slots 1330 thatextend in a linear row, along tissue contacting surface 1314. Staples1325 a have leg lengths that are longer than the leg lengths of staples1325 b and are disposed further away from the knife channel 1318, ascompared to staples 1325 b. In the embodiment shown in FIGS. 23-31, thestaple cartridge 1310 further has staples 1325 c, which have leg lengthsthat are shorter than the leg lengths of staples 1325 a and 1325 b, andare disposed adjacent the knife channel 1318. As shown in FIG. 31, whenthe staples are deployed and formed in tissue, the smaller staples 1325c are disposed adjacent the cut line in the tissue, with theintermediate-sized staples 1325 b being adjacent to staples 1325 c andoutwardly from staples 1325 c with respect to the cut line. Staples 1325a, which are the largest staples, are disposed outwardly of the staples1325 b and 1325 c. This arrangement provides improved hemostasis in thetissue.

In a surgical stapling instrument such as surgical stapling instrument300 (FIG. 5) or surgical stapling instrument 200 (FIG. 4), two linearrows of each size staple are provided, on opposite sides of the knifechannel 1318. As seen in FIG. 29, the staple cartridge 1310 has outertissue contacting surfaces 1312 a and 1312 b. Retention slots 1330housing staples 1325 a are defined in the outer tissue contactingsurfaces 1312 a and 1312 b. Retention slots 1330 housing staples 1325 bare defined in the intermediate tissue contacting surfaces 1314 a and1314 b. Retention slots 1330 housing staples 1325 c are defined in theinner tissue contacting surfaces 1316 a and 1316 b. Wall surface 1315 aprovides a sloping surface extending generally from the tissuecontacting surfaces 1312 a to tissue contacting surface 1314 a. A wallsurface 1315 b is arranged similarly on the opposite side of the knifechannel 1318, as shown in FIG. 29. Wall surface 1317 a extends generallybetween tissue contacting surfaces 1314 a and 1316 a and a similar wallsurface 1317 b is provided on the opposite side of the knife channel1318. The sloping wall surfaces 1315 a, 1315 b, 1317 a and 1317 bprovide a gradually varying compressive force on the tissue when thesurgical stapling instrument is used. When tissue is clamped betweenanvil member 1340 and staple cartridge 1310, fluid within the tissueflows generally outwardly and the sloping wall surfaces facilitate thisprocess.

In tool assemblies according to the present disclosure, staples havingdifferent leg lengths may be arranged so that the staples with thelarger leg lengths are arranged adjacent the knife channel. In addition,the staple cartridge may have a single planar tissue contacting surfaceand the anvil member may be provided with more than one tissuecontacting surface so as to define more than one gap with respect to thetissue contacting surface of the staple cartridge. One or both of thestaple cartridge and anvil member may have stepped surfaces, angled orsloped surfaces, or curved surfaces that are selected to correspond tostaples having predetermined leg lengths. In certain embodiments, morethan one tissue contacting surface is provided, on the staple cartridge,the anvil member, or both, with sloped surfaces extending therebetween.In certain embodiments, the staple pushers have heights corresponding tothe different staple sizes.

Referring additionally to FIG. 31, following the firing of surgicalstapling instrument 1300, the resulting tissue interface is seen incross-section. Accordingly, some or all of surgical fasteners 1325a-1325 c serve to hold tissues “A” and “B” to one another while thesurgical fasteners also provide the hemostasis.

All of the presently disclosed embodiments of the surgical staplinginstrument provide a variable pressure gradient (i.e. load profile) tothe layers of tissue that are joined together with the surgicalfasteners. Therefore, the layers of tissue that are proximate to thecenter of the surgical stapling instrument (i.e. center of the staplecartridge) are subjected to higher compressive forces (i.e. loads),thereby forming thinner layers of tissue as compared to layers of tissuethat are further away from the center of the surgical staplinginstrument. Since the layers of tissue nearest the center of thesurgical stapling instrument can be compressed more, a smaller sizedsurgical staple or fastener can be used to mechanically suture (i.e.fasten) the transected layers of tissue. Further still, providing agradual compression gradient to the layers of tissue to be joined (seeFIG. 16B), may result in a higher degree of hemostasis. Due to thecontoured shape of the staple cartridge, the layers of tissue can becompressed more at the center of the surgical stapling instrument,because the layers of tissue can translate (i.e. move) from a region ofrelatively high pressure (i.e. at the center) to a region of relativelylow pressure (i.e. at the edges) as the anvil member is moved relativeto the staple cartridge, thereby defining the pressure gradient.

In a further embodiment, the staple cartridge 1410 is as shown above inFIGS. 23-31, except that the wall surfaces 1417 a and 1417 b are convex,non-planar surfaces. (See FIG. 32). It is contemplated that any of thewall surfaces 1415 a, 1417 a, 1415 b and 1417 b are non-planar and maybe concave or convex. The tissue contacting surfaces 1412 a, 1414 a,1416 a, 1412 a, 1414 a, and/or 1416 a may also be planar or non-planar.

FIG. 32 also shows an angle A between wall surface 1315 b and areference line, which is shown as a vertical line, as well as an angle Bbetween wall surface 1317 b and the reference line. Angle A is desirablygreater than angle B. In one preferred embodiment, angle A is about 63degrees and angle B is about 42 degrees.

In addition, while each of the surgical stapling instruments describedabove and shown herein include tissue contacting surfaces having astepped profile, it is envisioned that any of the surgical staplinginstruments disclosed herein can have tissue contacting surfaces havingany one of a number of profiles including and not limited to angles,conical, tapered, arcuate and the like, as disclosed in commonlyassigned U.S. patent application Ser. No. 10/411,686, filed on May 11,2003, entitled “Surgical Stapling Apparatus Including an Anvil andCartridge Each Having Cooperating Mating Surfaces,” currently assignedto Tyco Healthcare Group LP, the entire contents of which isincorporated herein by reference.

It will be understood that various modifications may be made to theembodiments of the presently disclosed surgical stapling instruments.Therefore, the above description should not be construed as limiting,but merely as exemplifications of embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of thepresent disclosure.

What is claimed is:
 1. An apparatus for joining tubular tissue sectionscomprising: an anvil assembly including a radially stepped first tissuecontacting surface defining fastener forming recesses; and a cartridgeassembly having a second tissue contacting surface complementary to theradially stepped first tissue contacting surface, the second tissuecontacting surface defining a plurality of retention slots, each of theplurality of retention slots configured to receive a surgical fastenertherein; and a plurality of surgical fasteners, each of the plurality ofsurgical fasteners disposed in a respective one of the plurality ofretention slots, wherein at least some of the plurality of surgicalfasteners have different dimensions than others of the plurality ofsurgical fasteners.
 2. The apparatus according to claim 1, wherein eachof the first and second tissue contacting surfaces includes a firstsurface and a second surface positioned radially outward of the firstsurface.
 3. The apparatus according to claim 2, wherein the firstsurface of the second tissue contacting surface is positioned distallyof the second surface of the second tissue contacting surface.
 4. Theapparatus according to claim 3, wherein the first surface of the firsttissue contacting surface is positioned distally of the second surfaceof the first tissue contacting surface.
 5. The apparatus according toclaim 2, wherein the first and second surfaces of the second tissuecontacting surface are parallel to each other.
 6. The apparatusaccording to claim 2, wherein the first and second surfaces of the firsttissue contacting surface are parallel to each other.
 7. The apparatusaccording to claim 2, wherein each of the first and second surfaces ofthe first tissue contacting surface defines an annular array of thefastener forming recesses.
 8. The apparatus according to claim 7,wherein a first surgical fastener of the plurality of surgical fastenershas a first length and is formed against one of the fastener formingrecesses defined in the first surface of the first tissue contactingsurface, and a second surgical fastener of the plurality of surgicalfasteners has a second length and is formed against one of the fastenerforming recesses defined in the second surface of the first tissuecontacting surface, the first and second lengths being different.
 9. Theapparatus according to claim 8, wherein the first length is smaller thanthe second length.
 10. The apparatus according to claim 7, wherein theannular array of the fastener forming recesses on the respective firstand second surfaces of the first tissue contacting surface is on acommon plane.
 11. The apparatus according to claim 2, wherein the secondsurface of the first tissue contacting surface is disposed radiallyoutward of the first surface of the second tissue contacting surface.12. The apparatus according to claim 2, wherein each of the first andsecond surfaces of the second tissue contacting surface defines anannular array of the retention slots on a common plane.
 13. Theapparatus according to claim 1, further including a handle assembly anda tubular body portion extending from the handle assembly, wherein thetubular body portion supports the cartridge assembly.
 14. The apparatusaccording to claim 13, wherein the anvil assembly further includes ananvil shaft operatively coupling the anvil assembly with the handleassembly.
 15. The apparatus according to claim 1, wherein the cartridgeassembly further includes a staple ejection assembly having a pluralityof pushers, each of the plurality of pushers disposed within arespective one of the plurality of retention slots.
 16. The apparatusaccording to claim 1, wherein each of the first and second tissuecontacting surfaces includes an outer surface, an intermediate surface,and an inner surface, the outer surface being radially outward of theintermediate surface, the inner surface being radially inward of theintermediate surface.
 17. The apparatus according to claim 16, whereinthe outer surface is positioned proximally of the intermediate surface.18. The apparatus according to claim 17, wherein the intermediatesurface is positioned proximally of the inner surface.
 19. The apparatusaccording to claim 16, wherein each of the outer, intermediate, andinner surfaces of the first tissue contacting surface defines an annulararray of the fastener forming recesses.